[C++] Split flatbuffers.h into separate files (#6868)

* split flatbuffers.h into separate files

* wrong variable in cmakelists for android

* readded two accidentally deleted includes

* created buffer.h and moved buffer related things over

21 files changed, 3218 insertions, 2810 deletions

diff --git a/BUILD.bazel b/BUILD.bazel
index 395008cc..9b7c1232 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -37,8 +37,15 @@ cc_library(
 filegroup(
     name = "public_headers",
     srcs = [
+        "include/flatbuffers/allocator.h",
+        "include/flatbuffers/array.h",
         "include/flatbuffers/base.h",
+        "include/flatbuffers/buffer.h",
+        "include/flatbuffers/buffer_ref.h",
         "include/flatbuffers/code_generators.h",
+        "include/flatbuffers/default_allocator.h",
+        "include/flatbuffers/detached_buffer.h",
+        "include/flatbuffers/flatbuffer_builder.h",
         "include/flatbuffers/flatbuffers.h",
         "include/flatbuffers/flexbuffers.h",
         "include/flatbuffers/grpc.h",
@@ -49,7 +56,13 @@ filegroup(
         "include/flatbuffers/reflection_generated.h",
         "include/flatbuffers/registry.h",
         "include/flatbuffers/stl_emulation.h",
+        "include/flatbuffers/string.h",
+        "include/flatbuffers/struct.h",
+        "include/flatbuffers/table.h",
         "include/flatbuffers/util.h",
+        "include/flatbuffers/vector.h",
+        "include/flatbuffers/vector_downward.h",
+        "include/flatbuffers/verifier.h",
     ],
 )
 
@@ -87,6 +100,8 @@ cc_library(
         "include/flatbuffers/flexbuffers.h",
         "include/flatbuffers/stl_emulation.h",
         "include/flatbuffers/util.h",
+        "include/flatbuffers/vector.h",
+        "include/flatbuffers/verifier.h",
     ],
     linkstatic = 1,
     strip_include_prefix = "/include",
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 61531c62..44d72c24 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -73,17 +73,30 @@ endif()
 add_definitions(-DFLATBUFFERS_LOCALE_INDEPENDENT=$<BOOL:${FLATBUFFERS_LOCALE_INDEPENDENT}>)
 
 set(FlatBuffers_Library_SRCS
+  include/flatbuffers/allocator.h
+  include/flatbuffers/array.h
   include/flatbuffers/base.h
+  include/flatbuffers/buffer.h
+  include/flatbuffers/buffer_ref.h
+  include/flatbuffers/default_allocator.h
+  include/flatbuffers/detached_buffer.h
+  include/flatbuffers/flatbuffer_builder.h
   include/flatbuffers/flatbuffers.h
+  include/flatbuffers/flexbuffers.h
   include/flatbuffers/hash.h
   include/flatbuffers/idl.h
-  include/flatbuffers/util.h
+  include/flatbuffers/minireflect.h
   include/flatbuffers/reflection.h
   include/flatbuffers/reflection_generated.h
-  include/flatbuffers/stl_emulation.h
-  include/flatbuffers/flexbuffers.h
   include/flatbuffers/registry.h
-  include/flatbuffers/minireflect.h
+  include/flatbuffers/stl_emulation.h
+  include/flatbuffers/string.h
+  include/flatbuffers/struct.h
+  include/flatbuffers/table.h
+  include/flatbuffers/util.h
+  include/flatbuffers/vector.h
+  include/flatbuffers/vector_downward.h
+  include/flatbuffers/verifier.h
   src/idl_parser.cpp
   src/idl_gen_text.cpp
   src/reflection.cpp
diff --git a/android/app/src/main/cpp/flatbuffers/CMakeLists.txt b/android/app/src/main/cpp/flatbuffers/CMakeLists.txt
index f32b0bbb..7ce2a2c9 100644
--- a/android/app/src/main/cpp/flatbuffers/CMakeLists.txt
+++ b/android/app/src/main/cpp/flatbuffers/CMakeLists.txt
@@ -15,17 +15,30 @@ set(CMAKE_CXX_FLAGS
    "${CMAKE_CXX_FLAGS} -fsigned-char")
 
 set(FlatBuffers_Library_SRCS
+        ${FLATBUFFERS_SRC}/include/flatbuffers/allocator.h
+        ${FLATBUFFERS_SRC}/include/flatbuffers/array.h
         ${FLATBUFFERS_SRC}/include/flatbuffers/base.h
+        ${FLATBUFFERS_SRC}/include/flatbuffers/buffer.h
+        ${FLATBUFFERS_SRC}/include/flatbuffers/buffer_ref.h
+        ${FLATBUFFERS_SRC}/include/flatbuffers/default_allocator.h
+        ${FLATBUFFERS_SRC}/include/flatbuffers/detached_buffer.h
+        ${FLATBUFFERS_SRC}/include/flatbuffers/flatbuffer_builder.h
         ${FLATBUFFERS_SRC}/include/flatbuffers/flatbuffers.h
+        ${FLATBUFFERS_SRC}/include/flatbuffers/flexbuffers.h
         ${FLATBUFFERS_SRC}/include/flatbuffers/hash.h
         ${FLATBUFFERS_SRC}/include/flatbuffers/idl.h
-        ${FLATBUFFERS_SRC}/include/flatbuffers/util.h
+        ${FLATBUFFERS_SRC}/include/flatbuffers/minireflect.h
         ${FLATBUFFERS_SRC}/include/flatbuffers/reflection.h
         ${FLATBUFFERS_SRC}/include/flatbuffers/reflection_generated.h
-        ${FLATBUFFERS_SRC}/include/flatbuffers/stl_emulation.h
-        ${FLATBUFFERS_SRC}/include/flatbuffers/flexbuffers.h
         ${FLATBUFFERS_SRC}/include/flatbuffers/registry.h
-        ${FLATBUFFERS_SRC}/include/flatbuffers/minireflect.h
+        ${FLATBUFFERS_SRC}/include/flatbuffers/stl_emulation.h
+        ${FLATBUFFERS_SRC}/include/flatbuffers/string.h
+        ${FLATBUFFERS_SRC}/include/flatbuffers/struct.h
+        ${FLATBUFFERS_SRC}/include/flatbuffers/table.h
+        ${FLATBUFFERS_SRC}/include/flatbuffers/util.h
+        ${FLATBUFFERS_SRC}/include/flatbuffers/vector.h
+        ${FLATBUFFERS_SRC}/include/flatbuffers/vector_downward.h
+        ${FLATBUFFERS_SRC}/include/flatbuffers/verifier.h
         ${FLATBUFFERS_SRC}/src/idl_parser.cpp
         ${FLATBUFFERS_SRC}/src/idl_gen_text.cpp
         ${FLATBUFFERS_SRC}/src/reflection.cpp
diff --git a/include/flatbuffers/allocator.h b/include/flatbuffers/allocator.h
new file mode 100644
index 00000000..f4ef22db
--- /dev/null
+++ b/include/flatbuffers/allocator.h
@@ -0,0 +1,68 @@
+/*
+ * Copyright 2021 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FLATBUFFERS_ALLOCATOR_H_
+#define FLATBUFFERS_ALLOCATOR_H_
+
+#include "flatbuffers/base.h"
+
+namespace flatbuffers {
+
+// Allocator interface. This is flatbuffers-specific and meant only for
+// `vector_downward` usage.
+class Allocator {
+ public:
+  virtual ~Allocator() {}
+
+  // Allocate `size` bytes of memory.
+  virtual uint8_t *allocate(size_t size) = 0;
+
+  // Deallocate `size` bytes of memory at `p` allocated by this allocator.
+  virtual void deallocate(uint8_t *p, size_t size) = 0;
+
+  // Reallocate `new_size` bytes of memory, replacing the old region of size
+  // `old_size` at `p`. In contrast to a normal realloc, this grows downwards,
+  // and is intended specifcally for `vector_downward` use.
+  // `in_use_back` and `in_use_front` indicate how much of `old_size` is
+  // actually in use at each end, and needs to be copied.
+  virtual uint8_t *reallocate_downward(uint8_t *old_p, size_t old_size,
+                                       size_t new_size, size_t in_use_back,
+                                       size_t in_use_front) {
+    FLATBUFFERS_ASSERT(new_size > old_size);  // vector_downward only grows
+    uint8_t *new_p = allocate(new_size);
+    memcpy_downward(old_p, old_size, new_p, new_size, in_use_back,
+                    in_use_front);
+    deallocate(old_p, old_size);
+    return new_p;
+  }
+
+ protected:
+  // Called by `reallocate_downward` to copy memory from `old_p` of `old_size`
+  // to `new_p` of `new_size`. Only memory of size `in_use_front` and
+  // `in_use_back` will be copied from the front and back of the old memory
+  // allocation.
+  void memcpy_downward(uint8_t *old_p, size_t old_size, uint8_t *new_p,
+                       size_t new_size, size_t in_use_back,
+                       size_t in_use_front) {
+    memcpy(new_p + new_size - in_use_back, old_p + old_size - in_use_back,
+           in_use_back);
+    memcpy(new_p, old_p, in_use_front);
+  }
+};
+
+}  // namespace flatbuffers
+
+#endif  // FLATBUFFERS_ALLOCATOR_H_
\ No newline at end of file
diff --git a/include/flatbuffers/array.h b/include/flatbuffers/array.h
new file mode 100644
index 00000000..d4b73fc9
--- /dev/null
+++ b/include/flatbuffers/array.h
@@ -0,0 +1,243 @@
+/*
+ * Copyright 2021 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FLATBUFFERS_ARRAY_H_
+#define FLATBUFFERS_ARRAY_H_
+
+#include "flatbuffers/base.h"
+#include "flatbuffers/stl_emulation.h"
+#include "flatbuffers/vector.h"
+
+namespace flatbuffers {
+
+// This is used as a helper type for accessing arrays.
+template<typename T, uint16_t length> class Array {
+  // Array<T> can carry only POD data types (scalars or structs).
+  typedef typename flatbuffers::bool_constant<flatbuffers::is_scalar<T>::value>
+      scalar_tag;
+  typedef
+      typename flatbuffers::conditional<scalar_tag::value, T, const T *>::type
+          IndirectHelperType;
+
+ public:
+  typedef uint16_t size_type;
+  typedef typename IndirectHelper<IndirectHelperType>::return_type return_type;
+  typedef VectorIterator<T, return_type> const_iterator;
+  typedef VectorReverseIterator<const_iterator> const_reverse_iterator;
+
+  // If T is a LE-scalar or a struct (!scalar_tag::value).
+  static FLATBUFFERS_CONSTEXPR bool is_span_observable =
+      (scalar_tag::value && (FLATBUFFERS_LITTLEENDIAN || sizeof(T) == 1)) ||
+      !scalar_tag::value;
+
+  FLATBUFFERS_CONSTEXPR uint16_t size() const { return length; }
+
+  return_type Get(uoffset_t i) const {
+    FLATBUFFERS_ASSERT(i < size());
+    return IndirectHelper<IndirectHelperType>::Read(Data(), i);
+  }
+
+  return_type operator[](uoffset_t i) const { return Get(i); }
+
+  // If this is a Vector of enums, T will be its storage type, not the enum
+  // type. This function makes it convenient to retrieve value with enum
+  // type E.
+  template<typename E> E GetEnum(uoffset_t i) const {
+    return static_cast<E>(Get(i));
+  }
+
+  const_iterator begin() const { return const_iterator(Data(), 0); }
+  const_iterator end() const { return const_iterator(Data(), size()); }
+
+  const_reverse_iterator rbegin() const {
+    return const_reverse_iterator(end());
+  }
+  const_reverse_iterator rend() const {
+    return const_reverse_iterator(begin());
+  }
+
+  const_iterator cbegin() const { return begin(); }
+  const_iterator cend() const { return end(); }
+
+  const_reverse_iterator crbegin() const { return rbegin(); }
+  const_reverse_iterator crend() const { return rend(); }
+
+  // Get a mutable pointer to elements inside this array.
+  // This method used to mutate arrays of structs followed by a @p Mutate
+  // operation. For primitive types use @p Mutate directly.
+  // @warning Assignments and reads to/from the dereferenced pointer are not
+  //  automatically converted to the correct endianness.
+  typename flatbuffers::conditional<scalar_tag::value, void, T *>::type
+  GetMutablePointer(uoffset_t i) const {
+    FLATBUFFERS_ASSERT(i < size());
+    return const_cast<T *>(&data()[i]);
+  }
+
+  // Change elements if you have a non-const pointer to this object.
+  void Mutate(uoffset_t i, const T &val) { MutateImpl(scalar_tag(), i, val); }
+
+  // The raw data in little endian format. Use with care.
+  const uint8_t *Data() const { return data_; }
+
+  uint8_t *Data() { return data_; }
+
+  // Similarly, but typed, much like std::vector::data
+  const T *data() const { return reinterpret_cast<const T *>(Data()); }
+  T *data() { return reinterpret_cast<T *>(Data()); }
+
+  // Copy data from a span with endian conversion.
+  // If this Array and the span overlap, the behavior is undefined.
+  void CopyFromSpan(flatbuffers::span<const T, length> src) {
+    const auto p1 = reinterpret_cast<const uint8_t *>(src.data());
+    const auto p2 = Data();
+    FLATBUFFERS_ASSERT(!(p1 >= p2 && p1 < (p2 + length)) &&
+                       !(p2 >= p1 && p2 < (p1 + length)));
+    (void)p1;
+    (void)p2;
+    CopyFromSpanImpl(flatbuffers::bool_constant<is_span_observable>(), src);
+  }
+
+ protected:
+  void MutateImpl(flatbuffers::true_type, uoffset_t i, const T &val) {
+    FLATBUFFERS_ASSERT(i < size());
+    WriteScalar(data() + i, val);
+  }
+
+  void MutateImpl(flatbuffers::false_type, uoffset_t i, const T &val) {
+    *(GetMutablePointer(i)) = val;
+  }
+
+  void CopyFromSpanImpl(flatbuffers::true_type,
+                        flatbuffers::span<const T, length> src) {
+    // Use std::memcpy() instead of std::copy() to avoid performance degradation
+    // due to aliasing if T is char or unsigned char.
+    // The size is known at compile time, so memcpy would be inlined.
+    std::memcpy(data(), src.data(), length * sizeof(T));
+  }
+
+  // Copy data from flatbuffers::span with endian conversion.
+  void CopyFromSpanImpl(flatbuffers::false_type,
+                        flatbuffers::span<const T, length> src) {
+    for (size_type k = 0; k < length; k++) { Mutate(k, src[k]); }
+  }
+
+  // This class is only used to access pre-existing data. Don't ever
+  // try to construct these manually.
+  // 'constexpr' allows us to use 'size()' at compile time.
+  // @note Must not use 'FLATBUFFERS_CONSTEXPR' here, as const is not allowed on
+  //  a constructor.
+#if defined(__cpp_constexpr)
+  constexpr Array();
+#else
+  Array();
+#endif
+
+  uint8_t data_[length * sizeof(T)];
+
+ private:
+  // This class is a pointer. Copying will therefore create an invalid object.
+  // Private and unimplemented copy constructor.
+  Array(const Array &);
+  Array &operator=(const Array &);
+};
+
+// Specialization for Array[struct] with access using Offset<void> pointer.
+// This specialization used by idl_gen_text.cpp.
+template<typename T, uint16_t length> class Array<Offset<T>, length> {
+  static_assert(flatbuffers::is_same<T, void>::value, "unexpected type T");
+
+ public:
+  typedef const void *return_type;
+
+  const uint8_t *Data() const { return data_; }
+
+  // Make idl_gen_text.cpp::PrintContainer happy.
+  return_type operator[](uoffset_t) const {
+    FLATBUFFERS_ASSERT(false);
+    return nullptr;
+  }
+
+ private:
+  // This class is only used to access pre-existing data.
+  Array();
+  Array(const Array &);
+  Array &operator=(const Array &);
+
+  uint8_t data_[1];
+};
+
+template<class U, uint16_t N>
+FLATBUFFERS_CONSTEXPR_CPP11 flatbuffers::span<U, N> make_span(Array<U, N> &arr)
+    FLATBUFFERS_NOEXCEPT {
+  static_assert(
+      Array<U, N>::is_span_observable,
+      "wrong type U, only plain struct, LE-scalar, or byte types are allowed");
+  return span<U, N>(arr.data(), N);
+}
+
+template<class U, uint16_t N>
+FLATBUFFERS_CONSTEXPR_CPP11 flatbuffers::span<const U, N> make_span(
+    const Array<U, N> &arr) FLATBUFFERS_NOEXCEPT {
+  static_assert(
+      Array<U, N>::is_span_observable,
+      "wrong type U, only plain struct, LE-scalar, or byte types are allowed");
+  return span<const U, N>(arr.data(), N);
+}
+
+template<class U, uint16_t N>
+FLATBUFFERS_CONSTEXPR_CPP11 flatbuffers::span<uint8_t, sizeof(U) * N>
+make_bytes_span(Array<U, N> &arr) FLATBUFFERS_NOEXCEPT {
+  static_assert(Array<U, N>::is_span_observable,
+                "internal error, Array<T> might hold only scalars or structs");
+  return span<uint8_t, sizeof(U) * N>(arr.Data(), sizeof(U) * N);
+}
+
+template<class U, uint16_t N>
+FLATBUFFERS_CONSTEXPR_CPP11 flatbuffers::span<const uint8_t, sizeof(U) * N>
+make_bytes_span(const Array<U, N> &arr) FLATBUFFERS_NOEXCEPT {
+  static_assert(Array<U, N>::is_span_observable,
+                "internal error, Array<T> might hold only scalars or structs");
+  return span<const uint8_t, sizeof(U) * N>(arr.Data(), sizeof(U) * N);
+}
+
+// Cast a raw T[length] to a raw flatbuffers::Array<T, length>
+// without endian conversion. Use with care.
+// TODO: move these Cast-methods to `internal` namespace.
+template<typename T, uint16_t length>
+Array<T, length> &CastToArray(T (&arr)[length]) {
+  return *reinterpret_cast<Array<T, length> *>(arr);
+}
+
+template<typename T, uint16_t length>
+const Array<T, length> &CastToArray(const T (&arr)[length]) {
+  return *reinterpret_cast<const Array<T, length> *>(arr);
+}
+
+template<typename E, typename T, uint16_t length>
+Array<E, length> &CastToArrayOfEnum(T (&arr)[length]) {
+  static_assert(sizeof(E) == sizeof(T), "invalid enum type E");
+  return *reinterpret_cast<Array<E, length> *>(arr);
+}
+
+template<typename E, typename T, uint16_t length>
+const Array<E, length> &CastToArrayOfEnum(const T (&arr)[length]) {
+  static_assert(sizeof(E) == sizeof(T), "invalid enum type E");
+  return *reinterpret_cast<const Array<E, length> *>(arr);
+}
+
+}  // namespace flatbuffers
+
+#endif  // FLATBUFFERS_ARRAY_H_
diff --git a/include/flatbuffers/base.h b/include/flatbuffers/base.h
index de7898dc..5f5a009c 100644
--- a/include/flatbuffers/base.h
+++ b/include/flatbuffers/base.h
@@ -335,6 +335,9 @@ typedef uintmax_t largest_scalar_t;
 // We support aligning the contents of buffers up to this size.
 #define FLATBUFFERS_MAX_ALIGNMENT 16
 
+/// @brief The length of a FlatBuffer file header.
+static const size_t kFileIdentifierLength = 4;
+
 inline bool VerifyAlignmentRequirements(size_t align, size_t min_align = 1) {
   return (min_align <= align) && (align <= (FLATBUFFERS_MAX_ALIGNMENT)) &&
          (align & (align - 1)) == 0;  // must be power of 2
@@ -438,5 +441,38 @@ inline size_t PaddingBytes(size_t buf_size, size_t scalar_size) {
   return ((~buf_size) + 1) & (scalar_size - 1);
 }
 
+// Generic 'operator==' with conditional specialisations.
+// T e - new value of a scalar field.
+// T def - default of scalar (is known at compile-time).
+template<typename T> inline bool IsTheSameAs(T e, T def) { return e == def; }
+
+#if defined(FLATBUFFERS_NAN_DEFAULTS) && \
+    defined(FLATBUFFERS_HAS_NEW_STRTOD) && (FLATBUFFERS_HAS_NEW_STRTOD > 0)
+// Like `operator==(e, def)` with weak NaN if T=(float|double).
+template<typename T> inline bool IsFloatTheSameAs(T e, T def) {
+  return (e == def) || ((def != def) && (e != e));
+}
+template<> inline bool IsTheSameAs<float>(float e, float def) {
+  return IsFloatTheSameAs(e, def);
+}
+template<> inline bool IsTheSameAs<double>(double e, double def) {
+  return IsFloatTheSameAs(e, def);
+}
+#endif
+
+// Check 'v' is out of closed range [low; high].
+// Workaround for GCC warning [-Werror=type-limits]:
+// comparison is always true due to limited range of data type.
+template<typename T>
+inline bool IsOutRange(const T &v, const T &low, const T &high) {
+  return (v < low) || (high < v);
+}
+
+// Check 'v' is in closed range [low; high].
+template<typename T>
+inline bool IsInRange(const T &v, const T &low, const T &high) {
+  return !IsOutRange(v, low, high);
+}
+
 }  // namespace flatbuffers
 #endif  // FLATBUFFERS_BASE_H_
diff --git a/include/flatbuffers/buffer.h b/include/flatbuffers/buffer.h
new file mode 100644
index 00000000..e8d2ce9c
--- /dev/null
+++ b/include/flatbuffers/buffer.h
@@ -0,0 +1,142 @@
+/*
+ * Copyright 2021 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FLATBUFFERS_BUFFER_H_
+#define FLATBUFFERS_BUFFER_H_
+
+#include "flatbuffers/base.h"
+
+namespace flatbuffers {
+
+// Wrapper for uoffset_t to allow safe template specialization.
+// Value is allowed to be 0 to indicate a null object (see e.g. AddOffset).
+template<typename T> struct Offset {
+  uoffset_t o;
+  Offset() : o(0) {}
+  Offset(uoffset_t _o) : o(_o) {}
+  Offset<void> Union() const { return Offset<void>(o); }
+  bool IsNull() const { return !o; }
+};
+
+inline void EndianCheck() {
+  int endiantest = 1;
+  // If this fails, see FLATBUFFERS_LITTLEENDIAN above.
+  FLATBUFFERS_ASSERT(*reinterpret_cast<char *>(&endiantest) ==
+                     FLATBUFFERS_LITTLEENDIAN);
+  (void)endiantest;
+}
+
+template<typename T> FLATBUFFERS_CONSTEXPR size_t AlignOf() {
+  // clang-format off
+  #ifdef _MSC_VER
+    return __alignof(T);
+  #else
+    #ifndef alignof
+      return __alignof__(T);
+    #else
+      return alignof(T);
+    #endif
+  #endif
+  // clang-format on
+}
+
+// Lexicographically compare two strings (possibly containing nulls), and
+// return true if the first is less than the second.
+static inline bool StringLessThan(const char *a_data, uoffset_t a_size,
+                                  const char *b_data, uoffset_t b_size) {
+  const auto cmp = memcmp(a_data, b_data, (std::min)(a_size, b_size));
+  return cmp == 0 ? a_size < b_size : cmp < 0;
+}
+
+// When we read serialized data from memory, in the case of most scalars,
+// we want to just read T, but in the case of Offset, we want to actually
+// perform the indirection and return a pointer.
+// The template specialization below does just that.
+// It is wrapped in a struct since function templates can't overload on the
+// return type like this.
+// The typedef is for the convenience of callers of this function
+// (avoiding the need for a trailing return decltype)
+template<typename T> struct IndirectHelper {
+  typedef T return_type;
+  typedef T mutable_return_type;
+  static const size_t element_stride = sizeof(T);
+  static return_type Read(const uint8_t *p, uoffset_t i) {
+    return EndianScalar((reinterpret_cast<const T *>(p))[i]);
+  }
+};
+template<typename T> struct IndirectHelper<Offset<T>> {
+  typedef const T *return_type;
+  typedef T *mutable_return_type;
+  static const size_t element_stride = sizeof(uoffset_t);
+  static return_type Read(const uint8_t *p, uoffset_t i) {
+    p += i * sizeof(uoffset_t);
+    return reinterpret_cast<return_type>(p + ReadScalar<uoffset_t>(p));
+  }
+};
+template<typename T> struct IndirectHelper<const T *> {
+  typedef const T *return_type;
+  typedef T *mutable_return_type;
+  static const size_t element_stride = sizeof(T);
+  static return_type Read(const uint8_t *p, uoffset_t i) {
+    return reinterpret_cast<const T *>(p + i * sizeof(T));
+  }
+};
+
+/// @brief Get a pointer to the the file_identifier section of the buffer.
+/// @return Returns a const char pointer to the start of the file_identifier
+/// characters in the buffer.  The returned char * has length
+/// 'flatbuffers::FlatBufferBuilder::kFileIdentifierLength'.
+/// This function is UNDEFINED for FlatBuffers whose schema does not include
+/// a file_identifier (likely points at padding or the start of a the root
+/// vtable).
+inline const char *GetBufferIdentifier(const void *buf,
+                                       bool size_prefixed = false) {
+  return reinterpret_cast<const char *>(buf) +
+         ((size_prefixed) ? 2 * sizeof(uoffset_t) : sizeof(uoffset_t));
+}
+
+// Helper to see if the identifier in a buffer has the expected value.
+inline bool BufferHasIdentifier(const void *buf, const char *identifier,
+                                bool size_prefixed = false) {
+  return strncmp(GetBufferIdentifier(buf, size_prefixed), identifier,
+                 flatbuffers::kFileIdentifierLength) == 0;
+}
+
+/// @cond FLATBUFFERS_INTERNAL
+// Helpers to get a typed pointer to the root object contained in the buffer.
+template<typename T> T *GetMutableRoot(void *buf) {
+  EndianCheck();
+  return reinterpret_cast<T *>(
+      reinterpret_cast<uint8_t *>(buf) +
+      EndianScalar(*reinterpret_cast<uoffset_t *>(buf)));
+}
+
+template<typename T> T *GetMutableSizePrefixedRoot(void *buf) {
+  return GetMutableRoot<T>(reinterpret_cast<uint8_t *>(buf) +
+                           sizeof(uoffset_t));
+}
+
+template<typename T> const T *GetRoot(const void *buf) {
+  return GetMutableRoot<T>(const_cast<void *>(buf));
+}
+
+template<typename T> const T *GetSizePrefixedRoot(const void *buf) {
+  return GetRoot<T>(reinterpret_cast<const uint8_t *>(buf) + sizeof(uoffset_t));
+}
+
+}  // namespace flatbuffers
+
+#endif  // FLATBUFFERS_BUFFER_H_
\ No newline at end of file
diff --git a/include/flatbuffers/buffer_ref.h b/include/flatbuffers/buffer_ref.h
new file mode 100644
index 00000000..ce302073
--- /dev/null
+++ b/include/flatbuffers/buffer_ref.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2021 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FLATBUFFERS_BUFFER_REF_H_
+#define FLATBUFFERS_BUFFER_REF_H_
+
+#include "flatbuffers/base.h"
+#include "flatbuffers/verifier.h"
+
+namespace flatbuffers {
+
+// Convenient way to bundle a buffer and its length, to pass it around
+// typed by its root.
+// A BufferRef does not own its buffer.
+struct BufferRefBase {};  // for std::is_base_of
+
+template<typename T> struct BufferRef : BufferRefBase {
+  BufferRef() : buf(nullptr), len(0), must_free(false) {}
+  BufferRef(uint8_t *_buf, uoffset_t _len)
+      : buf(_buf), len(_len), must_free(false) {}
+
+  ~BufferRef() {
+    if (must_free) free(buf);
+  }
+
+  const T *GetRoot() const { return flatbuffers::GetRoot<T>(buf); }
+
+  bool Verify() {
+    Verifier verifier(buf, len);
+    return verifier.VerifyBuffer<T>(nullptr);
+  }
+
+  uint8_t *buf;
+  uoffset_t len;
+  bool must_free;
+};
+
+}  // namespace flatbuffers
+
+#endif  // FLATBUFFERS_BUFFER_REF_H_
\ No newline at end of file
diff --git a/include/flatbuffers/default_allocator.h b/include/flatbuffers/default_allocator.h
new file mode 100644
index 00000000..8b173af1
--- /dev/null
+++ b/include/flatbuffers/default_allocator.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2021 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FLATBUFFERS_DEFAULT_ALLOCATOR_H_
+#define FLATBUFFERS_DEFAULT_ALLOCATOR_H_
+
+#include "flatbuffers/allocator.h"
+#include "flatbuffers/base.h"
+
+namespace flatbuffers {
+
+// DefaultAllocator uses new/delete to allocate memory regions
+class DefaultAllocator : public Allocator {
+ public:
+  uint8_t *allocate(size_t size) FLATBUFFERS_OVERRIDE {
+    return new uint8_t[size];
+  }
+
+  void deallocate(uint8_t *p, size_t) FLATBUFFERS_OVERRIDE { delete[] p; }
+
+  static void dealloc(void *p, size_t) { delete[] static_cast<uint8_t *>(p); }
+};
+
+// These functions allow for a null allocator to mean use the default allocator,
+// as used by DetachedBuffer and vector_downward below.
+// This is to avoid having a statically or dynamically allocated default
+// allocator, or having to move it between the classes that may own it.
+inline uint8_t *Allocate(Allocator *allocator, size_t size) {
+  return allocator ? allocator->allocate(size)
+                   : DefaultAllocator().allocate(size);
+}
+
+inline void Deallocate(Allocator *allocator, uint8_t *p, size_t size) {
+  if (allocator)
+    allocator->deallocate(p, size);
+  else
+    DefaultAllocator().deallocate(p, size);
+}
+
+inline uint8_t *ReallocateDownward(Allocator *allocator, uint8_t *old_p,
+                                   size_t old_size, size_t new_size,
+                                   size_t in_use_back, size_t in_use_front) {
+  return allocator ? allocator->reallocate_downward(old_p, old_size, new_size,
+                                                    in_use_back, in_use_front)
+                   : DefaultAllocator().reallocate_downward(
+                         old_p, old_size, new_size, in_use_back, in_use_front);
+}
+
+}  // namespace flatbuffers
+
+#endif  // FLATBUFFERS_DEFAULT_ALLOCATOR_H_
\ No newline at end of file
diff --git a/include/flatbuffers/detached_buffer.h b/include/flatbuffers/detached_buffer.h
new file mode 100644
index 00000000..9d000293
--- /dev/null
+++ b/include/flatbuffers/detached_buffer.h
@@ -0,0 +1,132 @@
+/*
+ * Copyright 2021 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FLATBUFFERS_DETACHED_BUFFER_H_
+#define FLATBUFFERS_DETACHED_BUFFER_H_
+
+#include "flatbuffers/allocator.h"
+#include "flatbuffers/base.h"
+#include "flatbuffers/default_allocator.h"
+
+namespace flatbuffers {
+
+// DetachedBuffer is a finished flatbuffer memory region, detached from its
+// builder. The original memory region and allocator are also stored so that
+// the DetachedBuffer can manage the memory lifetime.
+class DetachedBuffer {
+ public:
+  DetachedBuffer()
+      : allocator_(nullptr),
+        own_allocator_(false),
+        buf_(nullptr),
+        reserved_(0),
+        cur_(nullptr),
+        size_(0) {}
+
+  DetachedBuffer(Allocator *allocator, bool own_allocator, uint8_t *buf,
+                 size_t reserved, uint8_t *cur, size_t sz)
+      : allocator_(allocator),
+        own_allocator_(own_allocator),
+        buf_(buf),
+        reserved_(reserved),
+        cur_(cur),
+        size_(sz) {}
+
+  // clang-format off
+  #if !defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+  DetachedBuffer(DetachedBuffer &&other)
+      : allocator_(other.allocator_),
+        own_allocator_(other.own_allocator_),
+        buf_(other.buf_),
+        reserved_(other.reserved_),
+        cur_(other.cur_),
+        size_(other.size_) {
+    other.reset();
+  }
+  // clang-format off
+  #endif  // !defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+
+  // clang-format off
+  #if !defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+  DetachedBuffer &operator=(DetachedBuffer &&other) {
+    if (this == &other) return *this;
+
+    destroy();
+
+    allocator_ = other.allocator_;
+    own_allocator_ = other.own_allocator_;
+    buf_ = other.buf_;
+    reserved_ = other.reserved_;
+    cur_ = other.cur_;
+    size_ = other.size_;
+
+    other.reset();
+
+    return *this;
+  }
+  // clang-format off
+  #endif  // !defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+
+  ~DetachedBuffer() { destroy(); }
+
+  const uint8_t *data() const { return cur_; }
+
+  uint8_t *data() { return cur_; }
+
+  size_t size() const { return size_; }
+
+  // clang-format off
+  #if !defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+  // These may change access mode, leave these at end of public section
+  FLATBUFFERS_DELETE_FUNC(DetachedBuffer(const DetachedBuffer &other));
+  FLATBUFFERS_DELETE_FUNC(
+      DetachedBuffer &operator=(const DetachedBuffer &other));
+  // clang-format off
+  #endif  // !defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+
+ protected:
+  Allocator *allocator_;
+  bool own_allocator_;
+  uint8_t *buf_;
+  size_t reserved_;
+  uint8_t *cur_;
+  size_t size_;
+
+  inline void destroy() {
+    if (buf_) Deallocate(allocator_, buf_, reserved_);
+    if (own_allocator_ && allocator_) { delete allocator_; }
+    reset();
+  }
+
+  inline void reset() {
+    allocator_ = nullptr;
+    own_allocator_ = false;
+    buf_ = nullptr;
+    reserved_ = 0;
+    cur_ = nullptr;
+    size_ = 0;
+  }
+};
+
+}  // namespace flatbuffers
+
+#endif  // FLATBUFFERS_DETACHED_BUFFER_H_
\ No newline at end of file
diff --git a/include/flatbuffers/flatbuffer_builder.h b/include/flatbuffers/flatbuffer_builder.h
new file mode 100644
index 00000000..caba8db6
--- /dev/null
+++ b/include/flatbuffers/flatbuffer_builder.h
@@ -0,0 +1,1201 @@
+/*
+ * Copyright 2021 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FLATBUFFERS_FLATBUFFER_BUILDER_H_
+#define FLATBUFFERS_FLATBUFFER_BUILDER_H_
+
+#include "flatbuffers/allocator.h"
+#include "flatbuffers/array.h"
+#include "flatbuffers/base.h"
+#include "flatbuffers/buffer_ref.h"
+#include "flatbuffers/default_allocator.h"
+#include "flatbuffers/detached_buffer.h"
+#include "flatbuffers/stl_emulation.h"
+#include "flatbuffers/string.h"
+#include "flatbuffers/struct.h"
+#include "flatbuffers/table.h"
+#include "flatbuffers/vector.h"
+#include "flatbuffers/vector_downward.h"
+#include "flatbuffers/verifier.h"
+
+#ifndef FLATBUFFERS_CPP98_STL
+#  include <functional>
+#endif
+
+namespace flatbuffers {
+
+// Converts a Field ID to a virtual table offset.
+inline voffset_t FieldIndexToOffset(voffset_t field_id) {
+  // Should correspond to what EndTable() below builds up.
+  const int fixed_fields = 2;  // Vtable size and Object Size.
+  return static_cast<voffset_t>((field_id + fixed_fields) * sizeof(voffset_t));
+}
+
+template<typename T, typename Alloc>
+const T *data(const std::vector<T, Alloc> &v) {
+  // Eventually the returned pointer gets passed down to memcpy, so
+  // we need it to be non-null to avoid undefined behavior.
+  static uint8_t t;
+  return v.empty() ? reinterpret_cast<const T *>(&t) : &v.front();
+}
+template<typename T, typename Alloc> T *data(std::vector<T, Alloc> &v) {
+  // Eventually the returned pointer gets passed down to memcpy, so
+  // we need it to be non-null to avoid undefined behavior.
+  static uint8_t t;
+  return v.empty() ? reinterpret_cast<T *>(&t) : &v.front();
+}
+
+/// @addtogroup flatbuffers_cpp_api
+/// @{
+/// @class FlatBufferBuilder
+/// @brief Helper class to hold data needed in creation of a FlatBuffer.
+/// To serialize data, you typically call one of the `Create*()` functions in
+/// the generated code, which in turn call a sequence of `StartTable`/
+/// `PushElement`/`AddElement`/`EndTable`, or the builtin `CreateString`/
+/// `CreateVector` functions. Do this is depth-first order to build up a tree to
+/// the root. `Finish()` wraps up the buffer ready for transport.
+class FlatBufferBuilder {
+ public:
+  /// @brief Default constructor for FlatBufferBuilder.
+  /// @param[in] initial_size The initial size of the buffer, in bytes. Defaults
+  /// to `1024`.
+  /// @param[in] allocator An `Allocator` to use. If null will use
+  /// `DefaultAllocator`.
+  /// @param[in] own_allocator Whether the builder/vector should own the
+  /// allocator. Defaults to / `false`.
+  /// @param[in] buffer_minalign Force the buffer to be aligned to the given
+  /// minimum alignment upon reallocation. Only needed if you intend to store
+  /// types with custom alignment AND you wish to read the buffer in-place
+  /// directly after creation.
+  explicit FlatBufferBuilder(
+      size_t initial_size = 1024, Allocator *allocator = nullptr,
+      bool own_allocator = false,
+      size_t buffer_minalign = AlignOf<largest_scalar_t>())
+      : buf_(initial_size, allocator, own_allocator, buffer_minalign),
+        num_field_loc(0),
+        max_voffset_(0),
+        nested(false),
+        finished(false),
+        minalign_(1),
+        force_defaults_(false),
+        dedup_vtables_(true),
+        string_pool(nullptr) {
+    EndianCheck();
+  }
+
+  // clang-format off
+  /// @brief Move constructor for FlatBufferBuilder.
+  #if !defined(FLATBUFFERS_CPP98_STL)
+  FlatBufferBuilder(FlatBufferBuilder &&other)
+  #else
+  FlatBufferBuilder(FlatBufferBuilder &other)
+  #endif  // #if !defined(FLATBUFFERS_CPP98_STL)
+    : buf_(1024, nullptr, false, AlignOf<largest_scalar_t>()),
+      num_field_loc(0),
+      max_voffset_(0),
+      nested(false),
+      finished(false),
+      minalign_(1),
+      force_defaults_(false),
+      dedup_vtables_(true),
+      string_pool(nullptr) {
+    EndianCheck();
+    // Default construct and swap idiom.
+    // Lack of delegating constructors in vs2010 makes it more verbose than needed.
+    Swap(other);
+  }
+  // clang-format on
+
+  // clang-format off
+  #if !defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+  /// @brief Move assignment operator for FlatBufferBuilder.
+  FlatBufferBuilder &operator=(FlatBufferBuilder &&other) {
+    // Move construct a temporary and swap idiom
+    FlatBufferBuilder temp(std::move(other));
+    Swap(temp);
+    return *this;
+  }
+  // clang-format off
+  #endif  // defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+
+  void Swap(FlatBufferBuilder &other) {
+    using std::swap;
+    buf_.swap(other.buf_);
+    swap(num_field_loc, other.num_field_loc);
+    swap(max_voffset_, other.max_voffset_);
+    swap(nested, other.nested);
+    swap(finished, other.finished);
+    swap(minalign_, other.minalign_);
+    swap(force_defaults_, other.force_defaults_);
+    swap(dedup_vtables_, other.dedup_vtables_);
+    swap(string_pool, other.string_pool);
+  }
+
+  ~FlatBufferBuilder() {
+    if (string_pool) delete string_pool;
+  }
+
+  void Reset() {
+    Clear();       // clear builder state
+    buf_.reset();  // deallocate buffer
+  }
+
+  /// @brief Reset all the state in this FlatBufferBuilder so it can be reused
+  /// to construct another buffer.
+  void Clear() {
+    ClearOffsets();
+    buf_.clear();
+    nested = false;
+    finished = false;
+    minalign_ = 1;
+    if (string_pool) string_pool->clear();
+  }
+
+  /// @brief The current size of the serialized buffer, counting from the end.
+  /// @return Returns an `uoffset_t` with the current size of the buffer.
+  uoffset_t GetSize() const { return buf_.size(); }
+
+  /// @brief Get the serialized buffer (after you call `Finish()`).
+  /// @return Returns an `uint8_t` pointer to the FlatBuffer data inside the
+  /// buffer.
+  uint8_t *GetBufferPointer() const {
+    Finished();
+    return buf_.data();
+  }
+
+  /// @brief Get the serialized buffer (after you call `Finish()`) as a span.
+  /// @return Returns a constructed flatbuffers::span that is a view over the
+  /// FlatBuffer data inside the buffer.
+  flatbuffers::span<uint8_t> GetBufferSpan() const {
+    Finished();
+    return flatbuffers::span<uint8_t>(buf_.data(), buf_.size());
+  }
+
+  /// @brief Get a pointer to an unfinished buffer.
+  /// @return Returns a `uint8_t` pointer to the unfinished buffer.
+  uint8_t *GetCurrentBufferPointer() const { return buf_.data(); }
+
+  /// @brief Get the released pointer to the serialized buffer.
+  /// @warning Do NOT attempt to use this FlatBufferBuilder afterwards!
+  /// @return A `FlatBuffer` that owns the buffer and its allocator and
+  /// behaves similar to a `unique_ptr` with a deleter.
+  FLATBUFFERS_ATTRIBUTE(deprecated("use Release() instead"))
+  DetachedBuffer ReleaseBufferPointer() {
+    Finished();
+    return buf_.release();
+  }
+
+  /// @brief Get the released DetachedBuffer.
+  /// @return A `DetachedBuffer` that owns the buffer and its allocator.
+  DetachedBuffer Release() {
+    Finished();
+    return buf_.release();
+  }
+
+  /// @brief Get the released pointer to the serialized buffer.
+  /// @param size The size of the memory block containing
+  /// the serialized `FlatBuffer`.
+  /// @param offset The offset from the released pointer where the finished
+  /// `FlatBuffer` starts.
+  /// @return A raw pointer to the start of the memory block containing
+  /// the serialized `FlatBuffer`.
+  /// @remark If the allocator is owned, it gets deleted when the destructor is
+  /// called..
+  uint8_t *ReleaseRaw(size_t &size, size_t &offset) {
+    Finished();
+    return buf_.release_raw(size, offset);
+  }
+
+  /// @brief get the minimum alignment this buffer needs to be accessed
+  /// properly. This is only known once all elements have been written (after
+  /// you call Finish()). You can use this information if you need to embed
+  /// a FlatBuffer in some other buffer, such that you can later read it
+  /// without first having to copy it into its own buffer.
+  size_t GetBufferMinAlignment() const {
+    Finished();
+    return minalign_;
+  }
+
+  /// @cond FLATBUFFERS_INTERNAL
+  void Finished() const {
+    // If you get this assert, you're attempting to get access a buffer
+    // which hasn't been finished yet. Be sure to call
+    // FlatBufferBuilder::Finish with your root table.
+    // If you really need to access an unfinished buffer, call
+    // GetCurrentBufferPointer instead.
+    FLATBUFFERS_ASSERT(finished);
+  }
+  /// @endcond
+
+  /// @brief In order to save space, fields that are set to their default value
+  /// don't get serialized into the buffer.
+  /// @param[in] fd When set to `true`, always serializes default values that
+  /// are set. Optional fields which are not set explicitly, will still not be
+  /// serialized.
+  void ForceDefaults(bool fd) { force_defaults_ = fd; }
+
+  /// @brief By default vtables are deduped in order to save space.
+  /// @param[in] dedup When set to `true`, dedup vtables.
+  void DedupVtables(bool dedup) { dedup_vtables_ = dedup; }
+
+  /// @cond FLATBUFFERS_INTERNAL
+  void Pad(size_t num_bytes) { buf_.fill(num_bytes); }
+
+  void TrackMinAlign(size_t elem_size) {
+    if (elem_size > minalign_) minalign_ = elem_size;
+  }
+
+  void Align(size_t elem_size) {
+    TrackMinAlign(elem_size);
+    buf_.fill(PaddingBytes(buf_.size(), elem_size));
+  }
+
+  void PushFlatBuffer(const uint8_t *bytes, size_t size) {
+    PushBytes(bytes, size);
+    finished = true;
+  }
+
+  void PushBytes(const uint8_t *bytes, size_t size) { buf_.push(bytes, size); }
+
+  void PopBytes(size_t amount) { buf_.pop(amount); }
+
+  template<typename T> void AssertScalarT() {
+    // The code assumes power of 2 sizes and endian-swap-ability.
+    static_assert(flatbuffers::is_scalar<T>::value, "T must be a scalar type");
+  }
+
+  // Write a single aligned scalar to the buffer
+  template<typename T> uoffset_t PushElement(T element) {
+    AssertScalarT<T>();
+    Align(sizeof(T));
+    buf_.push_small(EndianScalar(element));
+    return GetSize();
+  }
+
+  template<typename T> uoffset_t PushElement(Offset<T> off) {
+    // Special case for offsets: see ReferTo below.
+    return PushElement(ReferTo(off.o));
+  }
+
+  // When writing fields, we track where they are, so we can create correct
+  // vtables later.
+  void TrackField(voffset_t field, uoffset_t off) {
+    FieldLoc fl = { off, field };
+    buf_.scratch_push_small(fl);
+    num_field_loc++;
+    max_voffset_ = (std::max)(max_voffset_, field);
+  }
+
+  // Like PushElement, but additionally tracks the field this represents.
+  template<typename T> void AddElement(voffset_t field, T e, T def) {
+    // We don't serialize values equal to the default.
+    if (IsTheSameAs(e, def) && !force_defaults_) return;
+    auto off = PushElement(e);
+    TrackField(field, off);
+  }
+
+  template<typename T> void AddElement(voffset_t field, T e) {
+    auto off = PushElement(e);
+    TrackField(field, off);
+  }
+
+  template<typename T> void AddOffset(voffset_t field, Offset<T> off) {
+    if (off.IsNull()) return;  // Don't store.
+    AddElement(field, ReferTo(off.o), static_cast<uoffset_t>(0));
+  }
+
+  template<typename T> void AddStruct(voffset_t field, const T *structptr) {
+    if (!structptr) return;  // Default, don't store.
+    Align(AlignOf<T>());
+    buf_.push_small(*structptr);
+    TrackField(field, GetSize());
+  }
+
+  void AddStructOffset(voffset_t field, uoffset_t off) {
+    TrackField(field, off);
+  }
+
+  // Offsets initially are relative to the end of the buffer (downwards).
+  // This function converts them to be relative to the current location
+  // in the buffer (when stored here), pointing upwards.
+  uoffset_t ReferTo(uoffset_t off) {
+    // Align to ensure GetSize() below is correct.
+    Align(sizeof(uoffset_t));
+    // Offset must refer to something already in buffer.
+    FLATBUFFERS_ASSERT(off && off <= GetSize());
+    return GetSize() - off + static_cast<uoffset_t>(sizeof(uoffset_t));
+  }
+
+  void NotNested() {
+    // If you hit this, you're trying to construct a Table/Vector/String
+    // during the construction of its parent table (between the MyTableBuilder
+    // and table.Finish().
+    // Move the creation of these sub-objects to above the MyTableBuilder to
+    // not get this assert.
+    // Ignoring this assert may appear to work in simple cases, but the reason
+    // it is here is that storing objects in-line may cause vtable offsets
+    // to not fit anymore. It also leads to vtable duplication.
+    FLATBUFFERS_ASSERT(!nested);
+    // If you hit this, fields were added outside the scope of a table.
+    FLATBUFFERS_ASSERT(!num_field_loc);
+  }
+
+  // From generated code (or from the parser), we call StartTable/EndTable
+  // with a sequence of AddElement calls in between.
+  uoffset_t StartTable() {
+    NotNested();
+    nested = true;
+    return GetSize();
+  }
+
+  // This finishes one serialized object by generating the vtable if it's a
+  // table, comparing it against existing vtables, and writing the
+  // resulting vtable offset.
+  uoffset_t EndTable(uoffset_t start) {
+    // If you get this assert, a corresponding StartTable wasn't called.
+    FLATBUFFERS_ASSERT(nested);
+    // Write the vtable offset, which is the start of any Table.
+    // We fill it's value later.
+    auto vtableoffsetloc = PushElement<soffset_t>(0);
+    // Write a vtable, which consists entirely of voffset_t elements.
+    // It starts with the number of offsets, followed by a type id, followed
+    // by the offsets themselves. In reverse:
+    // Include space for the last offset and ensure empty tables have a
+    // minimum size.
+    max_voffset_ =
+        (std::max)(static_cast<voffset_t>(max_voffset_ + sizeof(voffset_t)),
+                   FieldIndexToOffset(0));
+    buf_.fill_big(max_voffset_);
+    auto table_object_size = vtableoffsetloc - start;
+    // Vtable use 16bit offsets.
+    FLATBUFFERS_ASSERT(table_object_size < 0x10000);
+    WriteScalar<voffset_t>(buf_.data() + sizeof(voffset_t),
+                           static_cast<voffset_t>(table_object_size));
+    WriteScalar<voffset_t>(buf_.data(), max_voffset_);
+    // Write the offsets into the table
+    for (auto it = buf_.scratch_end() - num_field_loc * sizeof(FieldLoc);
+         it < buf_.scratch_end(); it += sizeof(FieldLoc)) {
+      auto field_location = reinterpret_cast<FieldLoc *>(it);
+      auto pos = static_cast<voffset_t>(vtableoffsetloc - field_location->off);
+      // If this asserts, it means you've set a field twice.
+      FLATBUFFERS_ASSERT(
+          !ReadScalar<voffset_t>(buf_.data() + field_location->id));
+      WriteScalar<voffset_t>(buf_.data() + field_location->id, pos);
+    }
+    ClearOffsets();
+    auto vt1 = reinterpret_cast<voffset_t *>(buf_.data());
+    auto vt1_size = ReadScalar<voffset_t>(vt1);
+    auto vt_use = GetSize();
+    // See if we already have generated a vtable with this exact same
+    // layout before. If so, make it point to the old one, remove this one.
+    if (dedup_vtables_) {
+      for (auto it = buf_.scratch_data(); it < buf_.scratch_end();
+           it += sizeof(uoffset_t)) {
+        auto vt_offset_ptr = reinterpret_cast<uoffset_t *>(it);
+        auto vt2 = reinterpret_cast<voffset_t *>(buf_.data_at(*vt_offset_ptr));
+        auto vt2_size = ReadScalar<voffset_t>(vt2);
+        if (vt1_size != vt2_size || 0 != memcmp(vt2, vt1, vt1_size)) continue;
+        vt_use = *vt_offset_ptr;
+        buf_.pop(GetSize() - vtableoffsetloc);
+        break;
+      }
+    }
+    // If this is a new vtable, remember it.
+    if (vt_use == GetSize()) { buf_.scratch_push_small(vt_use); }
+    // Fill the vtable offset we created above.
+    // The offset points from the beginning of the object to where the
+    // vtable is stored.
+    // Offsets default direction is downward in memory for future format
+    // flexibility (storing all vtables at the start of the file).
+    WriteScalar(buf_.data_at(vtableoffsetloc),
+                static_cast<soffset_t>(vt_use) -
+                    static_cast<soffset_t>(vtableoffsetloc));
+
+    nested = false;
+    return vtableoffsetloc;
+  }
+
+  FLATBUFFERS_ATTRIBUTE(deprecated("call the version above instead"))
+  uoffset_t EndTable(uoffset_t start, voffset_t /*numfields*/) {
+    return EndTable(start);
+  }
+
+  // This checks a required field has been set in a given table that has
+  // just been constructed.
+  template<typename T> void Required(Offset<T> table, voffset_t field);
+
+  uoffset_t StartStruct(size_t alignment) {
+    Align(alignment);
+    return GetSize();
+  }
+
+  uoffset_t EndStruct() { return GetSize(); }
+
+  void ClearOffsets() {
+    buf_.scratch_pop(num_field_loc * sizeof(FieldLoc));
+    num_field_loc = 0;
+    max_voffset_ = 0;
+  }
+
+  // Aligns such that when "len" bytes are written, an object can be written
+  // after it with "alignment" without padding.
+  void PreAlign(size_t len, size_t alignment) {
+    TrackMinAlign(alignment);
+    buf_.fill(PaddingBytes(GetSize() + len, alignment));
+  }
+  template<typename T> void PreAlign(size_t len) {
+    AssertScalarT<T>();
+    PreAlign(len, sizeof(T));
+  }
+  /// @endcond
+
+  /// @brief Store a string in the buffer, which can contain any binary data.
+  /// @param[in] str A const char pointer to the data to be stored as a string.
+  /// @param[in] len The number of bytes that should be stored from `str`.
+  /// @return Returns the offset in the buffer where the string starts.
+  Offset<String> CreateString(const char *str, size_t len) {
+    NotNested();
+    PreAlign<uoffset_t>(len + 1);  // Always 0-terminated.
+    buf_.fill(1);
+    PushBytes(reinterpret_cast<const uint8_t *>(str), len);
+    PushElement(static_cast<uoffset_t>(len));
+    return Offset<String>(GetSize());
+  }
+
+  /// @brief Store a string in the buffer, which is null-terminated.
+  /// @param[in] str A const char pointer to a C-string to add to the buffer.
+  /// @return Returns the offset in the buffer where the string starts.
+  Offset<String> CreateString(const char *str) {
+    return CreateString(str, strlen(str));
+  }
+
+  /// @brief Store a string in the buffer, which is null-terminated.
+  /// @param[in] str A char pointer to a C-string to add to the buffer.
+  /// @return Returns the offset in the buffer where the string starts.
+  Offset<String> CreateString(char *str) {
+    return CreateString(str, strlen(str));
+  }
+
+  /// @brief Store a string in the buffer, which can contain any binary data.
+  /// @param[in] str A const reference to a std::string to store in the buffer.
+  /// @return Returns the offset in the buffer where the string starts.
+  Offset<String> CreateString(const std::string &str) {
+    return CreateString(str.c_str(), str.length());
+  }
+
+  // clang-format off
+  #ifdef FLATBUFFERS_HAS_STRING_VIEW
+  /// @brief Store a string in the buffer, which can contain any binary data.
+  /// @param[in] str A const string_view to copy in to the buffer.
+  /// @return Returns the offset in the buffer where the string starts.
+  Offset<String> CreateString(flatbuffers::string_view str) {
+    return CreateString(str.data(), str.size());
+  }
+  #endif // FLATBUFFERS_HAS_STRING_VIEW
+  // clang-format on
+
+  /// @brief Store a string in the buffer, which can contain any binary data.
+  /// @param[in] str A const pointer to a `String` struct to add to the buffer.
+  /// @return Returns the offset in the buffer where the string starts
+  Offset<String> CreateString(const String *str) {
+    return str ? CreateString(str->c_str(), str->size()) : 0;
+  }
+
+  /// @brief Store a string in the buffer, which can contain any binary data.
+  /// @param[in] str A const reference to a std::string like type with support
+  /// of T::c_str() and T::length() to store in the buffer.
+  /// @return Returns the offset in the buffer where the string starts.
+  template<typename T> Offset<String> CreateString(const T &str) {
+    return CreateString(str.c_str(), str.length());
+  }
+
+  /// @brief Store a string in the buffer, which can contain any binary data.
+  /// If a string with this exact contents has already been serialized before,
+  /// instead simply returns the offset of the existing string. This uses a map
+  /// stored on the heap, but only stores the numerical offsets.
+  /// @param[in] str A const char pointer to the data to be stored as a string.
+  /// @param[in] len The number of bytes that should be stored from `str`.
+  /// @return Returns the offset in the buffer where the string starts.
+  Offset<String> CreateSharedString(const char *str, size_t len) {
+    FLATBUFFERS_ASSERT(FLATBUFFERS_GENERAL_HEAP_ALLOC_OK);
+    if (!string_pool)
+      string_pool = new StringOffsetMap(StringOffsetCompare(buf_));
+    auto size_before_string = buf_.size();
+    // Must first serialize the string, since the set is all offsets into
+    // buffer.
+    auto off = CreateString(str, len);
+    auto it = string_pool->find(off);
+    // If it exists we reuse existing serialized data!
+    if (it != string_pool->end()) {
+      // We can remove the string we serialized.
+      buf_.pop(buf_.size() - size_before_string);
+      return *it;
+    }
+    // Record this string for future use.
+    string_pool->insert(off);
+    return off;
+  }
+
+#ifdef FLATBUFFERS_HAS_STRING_VIEW
+  /// @brief Store a string in the buffer, which can contain any binary data.
+  /// If a string with this exact contents has already been serialized before,
+  /// instead simply returns the offset of the existing string. This uses a map
+  /// stored on the heap, but only stores the numerical offsets.
+  /// @param[in] str A const std::string_view to store in the buffer.
+  /// @return Returns the offset in the buffer where the string starts
+  Offset<String> CreateSharedString(const flatbuffers::string_view str) {
+    return CreateSharedString(str.data(), str.size());
+  }
+#else
+  /// @brief Store a string in the buffer, which null-terminated.
+  /// If a string with this exact contents has already been serialized before,
+  /// instead simply returns the offset of the existing string. This uses a map
+  /// stored on the heap, but only stores the numerical offsets.
+  /// @param[in] str A const char pointer to a C-string to add to the buffer.
+  /// @return Returns the offset in the buffer where the string starts.
+  Offset<String> CreateSharedString(const char *str) {
+    return CreateSharedString(str, strlen(str));
+  }
+
+  /// @brief Store a string in the buffer, which can contain any binary data.
+  /// If a string with this exact contents has already been serialized before,
+  /// instead simply returns the offset of the existing string. This uses a map
+  /// stored on the heap, but only stores the numerical offsets.
+  /// @param[in] str A const reference to a std::string to store in the buffer.
+  /// @return Returns the offset in the buffer where the string starts.
+  Offset<String> CreateSharedString(const std::string &str) {
+    return CreateSharedString(str.c_str(), str.length());
+  }
+#endif
+
+  /// @brief Store a string in the buffer, which can contain any binary data.
+  /// If a string with this exact contents has already been serialized before,
+  /// instead simply returns the offset of the existing string. This uses a map
+  /// stored on the heap, but only stores the numerical offsets.
+  /// @param[in] str A const pointer to a `String` struct to add to the buffer.
+  /// @return Returns the offset in the buffer where the string starts
+  Offset<String> CreateSharedString(const String *str) {
+    return CreateSharedString(str->c_str(), str->size());
+  }
+
+  /// @cond FLATBUFFERS_INTERNAL
+  uoffset_t EndVector(size_t len) {
+    FLATBUFFERS_ASSERT(nested);  // Hit if no corresponding StartVector.
+    nested = false;
+    return PushElement(static_cast<uoffset_t>(len));
+  }
+
+  void StartVector(size_t len, size_t elemsize) {
+    NotNested();
+    nested = true;
+    PreAlign<uoffset_t>(len * elemsize);
+    PreAlign(len * elemsize, elemsize);  // Just in case elemsize > uoffset_t.
+  }
+
+  // Call this right before StartVector/CreateVector if you want to force the
+  // alignment to be something different than what the element size would
+  // normally dictate.
+  // This is useful when storing a nested_flatbuffer in a vector of bytes,
+  // or when storing SIMD floats, etc.
+  void ForceVectorAlignment(size_t len, size_t elemsize, size_t alignment) {
+    FLATBUFFERS_ASSERT(VerifyAlignmentRequirements(alignment));
+    PreAlign(len * elemsize, alignment);
+  }
+
+  // Similar to ForceVectorAlignment but for String fields.
+  void ForceStringAlignment(size_t len, size_t alignment) {
+    FLATBUFFERS_ASSERT(VerifyAlignmentRequirements(alignment));
+    PreAlign((len + 1) * sizeof(char), alignment);
+  }
+
+  /// @endcond
+
+  /// @brief Serialize an array into a FlatBuffer `vector`.
+  /// @tparam T The data type of the array elements.
+  /// @param[in] v A pointer to the array of type `T` to serialize into the
+  /// buffer as a `vector`.
+  /// @param[in] len The number of elements to serialize.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T> Offset<Vector<T>> CreateVector(const T *v, size_t len) {
+    // If this assert hits, you're specifying a template argument that is
+    // causing the wrong overload to be selected, remove it.
+    AssertScalarT<T>();
+    StartVector(len, sizeof(T));
+    if (len == 0) { return Offset<Vector<T>>(EndVector(len)); }
+    // clang-format off
+    #if FLATBUFFERS_LITTLEENDIAN
+      PushBytes(reinterpret_cast<const uint8_t *>(v), len * sizeof(T));
+    #else
+      if (sizeof(T) == 1) {
+        PushBytes(reinterpret_cast<const uint8_t *>(v), len);
+      } else {
+        for (auto i = len; i > 0; ) {
+          PushElement(v[--i]);
+        }
+      }
+    #endif
+    // clang-format on
+    return Offset<Vector<T>>(EndVector(len));
+  }
+
+  template<typename T>
+  Offset<Vector<Offset<T>>> CreateVector(const Offset<T> *v, size_t len) {
+    StartVector(len, sizeof(Offset<T>));
+    for (auto i = len; i > 0;) { PushElement(v[--i]); }
+    return Offset<Vector<Offset<T>>>(EndVector(len));
+  }
+
+  /// @brief Serialize a `std::vector` into a FlatBuffer `vector`.
+  /// @tparam T The data type of the `std::vector` elements.
+  /// @param v A const reference to the `std::vector` to serialize into the
+  /// buffer as a `vector`.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T, typename Alloc>
+  Offset<Vector<T>> CreateVector(const std::vector<T, Alloc> &v) {
+    return CreateVector(data(v), v.size());
+  }
+
+  // vector<bool> may be implemented using a bit-set, so we can't access it as
+  // an array. Instead, read elements manually.
+  // Background: https://isocpp.org/blog/2012/11/on-vectorbool
+  Offset<Vector<uint8_t>> CreateVector(const std::vector<bool> &v) {
+    StartVector(v.size(), sizeof(uint8_t));
+    for (auto i = v.size(); i > 0;) {
+      PushElement(static_cast<uint8_t>(v[--i]));
+    }
+    return Offset<Vector<uint8_t>>(EndVector(v.size()));
+  }
+
+  // clang-format off
+  #ifndef FLATBUFFERS_CPP98_STL
+  /// @brief Serialize values returned by a function into a FlatBuffer `vector`.
+  /// This is a convenience function that takes care of iteration for you.
+  /// @tparam T The data type of the `std::vector` elements.
+  /// @param f A function that takes the current iteration 0..vector_size-1 and
+  /// returns any type that you can construct a FlatBuffers vector out of.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T> Offset<Vector<T>> CreateVector(size_t vector_size,
+      const std::function<T (size_t i)> &f) {
+    FLATBUFFERS_ASSERT(FLATBUFFERS_GENERAL_HEAP_ALLOC_OK);
+    std::vector<T> elems(vector_size);
+    for (size_t i = 0; i < vector_size; i++) elems[i] = f(i);
+    return CreateVector(elems);
+  }
+  #endif // FLATBUFFERS_CPP98_STL
+  // clang-format on
+
+  /// @brief Serialize values returned by a function into a FlatBuffer `vector`.
+  /// This is a convenience function that takes care of iteration for you. This
+  /// uses a vector stored on the heap to store the intermediate results of the
+  /// iteration.
+  /// @tparam T The data type of the `std::vector` elements.
+  /// @param f A function that takes the current iteration 0..vector_size-1,
+  /// and the state parameter returning any type that you can construct a
+  /// FlatBuffers vector out of.
+  /// @param state State passed to f.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T, typename F, typename S>
+  Offset<Vector<T>> CreateVector(size_t vector_size, F f, S *state) {
+    FLATBUFFERS_ASSERT(FLATBUFFERS_GENERAL_HEAP_ALLOC_OK);
+    std::vector<T> elems(vector_size);
+    for (size_t i = 0; i < vector_size; i++) elems[i] = f(i, state);
+    return CreateVector(elems);
+  }
+
+  /// @brief Serialize a `std::vector<std::string>` into a FlatBuffer `vector`.
+  /// This is a convenience function for a common case.
+  /// @param v A const reference to the `std::vector` to serialize into the
+  /// buffer as a `vector`.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename Alloc>
+  Offset<Vector<Offset<String>>> CreateVectorOfStrings(
+      const std::vector<std::string, Alloc> &v) {
+    return CreateVectorOfStrings(v.cbegin(), v.cend());
+  }
+
+  /// @brief Serialize a collection of Strings into a FlatBuffer `vector`.
+  /// This is a convenience function for a common case.
+  /// @param begin The begining iterator of the collection
+  /// @param end The ending iterator of the collection
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<class It>
+  Offset<Vector<Offset<String>>> CreateVectorOfStrings(It begin, It end) {
+    auto size = std::distance(begin, end);
+    auto scratch_buffer_usage = size * sizeof(Offset<String>);
+    // If there is not enough space to store the offsets, there definitely won't
+    // be enough space to store all the strings. So ensuring space for the
+    // scratch region is OK, for it it fails, it would have failed later.
+    buf_.ensure_space(scratch_buffer_usage);
+    for (auto it = begin; it != end; ++it) {
+      buf_.scratch_push_small(CreateString(*it));
+    }
+    StartVector(size, sizeof(Offset<String>));
+    for (auto i = 1; i <= size; i++) {
+      // Note we re-evaluate the buf location each iteration to account for any
+      // underlying buffer resizing that may occur.
+      PushElement(*reinterpret_cast<Offset<String> *>(
+          buf_.scratch_end() - i * sizeof(Offset<String>)));
+    }
+    buf_.scratch_pop(scratch_buffer_usage);
+    return Offset<Vector<Offset<String>>>(EndVector(size));
+  }
+
+  /// @brief Serialize an array of structs into a FlatBuffer `vector`.
+  /// @tparam T The data type of the struct array elements.
+  /// @param[in] v A pointer to the array of type `T` to serialize into the
+  /// buffer as a `vector`.
+  /// @param[in] len The number of elements to serialize.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T>
+  Offset<Vector<const T *>> CreateVectorOfStructs(const T *v, size_t len) {
+    StartVector(len * sizeof(T) / AlignOf<T>(), AlignOf<T>());
+    if (len > 0) {
+      PushBytes(reinterpret_cast<const uint8_t *>(v), sizeof(T) * len);
+    }
+    return Offset<Vector<const T *>>(EndVector(len));
+  }
+
+  /// @brief Serialize an array of native structs into a FlatBuffer `vector`.
+  /// @tparam T The data type of the struct array elements.
+  /// @tparam S The data type of the native struct array elements.
+  /// @param[in] v A pointer to the array of type `S` to serialize into the
+  /// buffer as a `vector`.
+  /// @param[in] len The number of elements to serialize.
+  /// @param[in] pack_func Pointer to a function to convert the native struct
+  /// to the FlatBuffer struct.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T, typename S>
+  Offset<Vector<const T *>> CreateVectorOfNativeStructs(
+      const S *v, size_t len, T (*const pack_func)(const S &)) {
+    FLATBUFFERS_ASSERT(pack_func);
+    auto structs = StartVectorOfStructs<T>(len);
+    for (size_t i = 0; i < len; i++) { structs[i] = pack_func(v[i]); }
+    return EndVectorOfStructs<T>(len);
+  }
+
+  /// @brief Serialize an array of native structs into a FlatBuffer `vector`.
+  /// @tparam T The data type of the struct array elements.
+  /// @tparam S The data type of the native struct array elements.
+  /// @param[in] v A pointer to the array of type `S` to serialize into the
+  /// buffer as a `vector`.
+  /// @param[in] len The number of elements to serialize.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T, typename S>
+  Offset<Vector<const T *>> CreateVectorOfNativeStructs(const S *v,
+                                                        size_t len) {
+    extern T Pack(const S &);
+    return CreateVectorOfNativeStructs(v, len, Pack);
+  }
+
+  // clang-format off
+  #ifndef FLATBUFFERS_CPP98_STL
+  /// @brief Serialize an array of structs into a FlatBuffer `vector`.
+  /// @tparam T The data type of the struct array elements.
+  /// @param[in] filler A function that takes the current iteration 0..vector_size-1
+  /// and a pointer to the struct that must be filled.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  /// This is mostly useful when flatbuffers are generated with mutation
+  /// accessors.
+  template<typename T> Offset<Vector<const T *>> CreateVectorOfStructs(
+      size_t vector_size, const std::function<void(size_t i, T *)> &filler) {
+    T* structs = StartVectorOfStructs<T>(vector_size);
+    for (size_t i = 0; i < vector_size; i++) {
+      filler(i, structs);
+      structs++;
+    }
+    return EndVectorOfStructs<T>(vector_size);
+  }
+  #endif
+  // clang-format on
+
+  /// @brief Serialize an array of structs into a FlatBuffer `vector`.
+  /// @tparam T The data type of the struct array elements.
+  /// @param[in] f A function that takes the current iteration 0..vector_size-1,
+  /// a pointer to the struct that must be filled and the state argument.
+  /// @param[in] state Arbitrary state to pass to f.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  /// This is mostly useful when flatbuffers are generated with mutation
+  /// accessors.
+  template<typename T, typename F, typename S>
+  Offset<Vector<const T *>> CreateVectorOfStructs(size_t vector_size, F f,
+                                                  S *state) {
+    T *structs = StartVectorOfStructs<T>(vector_size);
+    for (size_t i = 0; i < vector_size; i++) {
+      f(i, structs, state);
+      structs++;
+    }
+    return EndVectorOfStructs<T>(vector_size);
+  }
+
+  /// @brief Serialize a `std::vector` of structs into a FlatBuffer `vector`.
+  /// @tparam T The data type of the `std::vector` struct elements.
+  /// @param[in] v A const reference to the `std::vector` of structs to
+  /// serialize into the buffer as a `vector`.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T, typename Alloc>
+  Offset<Vector<const T *>> CreateVectorOfStructs(
+      const std::vector<T, Alloc> &v) {
+    return CreateVectorOfStructs(data(v), v.size());
+  }
+
+  /// @brief Serialize a `std::vector` of native structs into a FlatBuffer
+  /// `vector`.
+  /// @tparam T The data type of the `std::vector` struct elements.
+  /// @tparam S The data type of the `std::vector` native struct elements.
+  /// @param[in] v A const reference to the `std::vector` of structs to
+  /// serialize into the buffer as a `vector`.
+  /// @param[in] pack_func Pointer to a function to convert the native struct
+  /// to the FlatBuffer struct.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T, typename S, typename Alloc>
+  Offset<Vector<const T *>> CreateVectorOfNativeStructs(
+      const std::vector<S, Alloc> &v, T (*const pack_func)(const S &)) {
+    return CreateVectorOfNativeStructs<T, S>(data(v), v.size(), pack_func);
+  }
+
+  /// @brief Serialize a `std::vector` of native structs into a FlatBuffer
+  /// `vector`.
+  /// @tparam T The data type of the `std::vector` struct elements.
+  /// @tparam S The data type of the `std::vector` native struct elements.
+  /// @param[in] v A const reference to the `std::vector` of structs to
+  /// serialize into the buffer as a `vector`.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T, typename S, typename Alloc>
+  Offset<Vector<const T *>> CreateVectorOfNativeStructs(
+      const std::vector<S, Alloc> &v) {
+    return CreateVectorOfNativeStructs<T, S>(data(v), v.size());
+  }
+
+  /// @cond FLATBUFFERS_INTERNAL
+  template<typename T> struct StructKeyComparator {
+    bool operator()(const T &a, const T &b) const {
+      return a.KeyCompareLessThan(&b);
+    }
+  };
+  /// @endcond
+
+  /// @brief Serialize a `std::vector` of structs into a FlatBuffer `vector`
+  /// in sorted order.
+  /// @tparam T The data type of the `std::vector` struct elements.
+  /// @param[in] v A const reference to the `std::vector` of structs to
+  /// serialize into the buffer as a `vector`.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T, typename Alloc>
+  Offset<Vector<const T *>> CreateVectorOfSortedStructs(
+      std::vector<T, Alloc> *v) {
+    return CreateVectorOfSortedStructs(data(*v), v->size());
+  }
+
+  /// @brief Serialize a `std::vector` of native structs into a FlatBuffer
+  /// `vector` in sorted order.
+  /// @tparam T The data type of the `std::vector` struct elements.
+  /// @tparam S The data type of the `std::vector` native struct elements.
+  /// @param[in] v A const reference to the `std::vector` of structs to
+  /// serialize into the buffer as a `vector`.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T, typename S, typename Alloc>
+  Offset<Vector<const T *>> CreateVectorOfSortedNativeStructs(
+      std::vector<S, Alloc> *v) {
+    return CreateVectorOfSortedNativeStructs<T, S>(data(*v), v->size());
+  }
+
+  /// @brief Serialize an array of structs into a FlatBuffer `vector` in sorted
+  /// order.
+  /// @tparam T The data type of the struct array elements.
+  /// @param[in] v A pointer to the array of type `T` to serialize into the
+  /// buffer as a `vector`.
+  /// @param[in] len The number of elements to serialize.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T>
+  Offset<Vector<const T *>> CreateVectorOfSortedStructs(T *v, size_t len) {
+    std::sort(v, v + len, StructKeyComparator<T>());
+    return CreateVectorOfStructs(v, len);
+  }
+
+  /// @brief Serialize an array of native structs into a FlatBuffer `vector` in
+  /// sorted order.
+  /// @tparam T The data type of the struct array elements.
+  /// @tparam S The data type of the native struct array elements.
+  /// @param[in] v A pointer to the array of type `S` to serialize into the
+  /// buffer as a `vector`.
+  /// @param[in] len The number of elements to serialize.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T, typename S>
+  Offset<Vector<const T *>> CreateVectorOfSortedNativeStructs(S *v,
+                                                              size_t len) {
+    extern T Pack(const S &);
+    auto structs = StartVectorOfStructs<T>(len);
+    for (size_t i = 0; i < len; i++) { structs[i] = Pack(v[i]); }
+    std::sort(structs, structs + len, StructKeyComparator<T>());
+    return EndVectorOfStructs<T>(len);
+  }
+
+  /// @cond FLATBUFFERS_INTERNAL
+  template<typename T> struct TableKeyComparator {
+    TableKeyComparator(vector_downward &buf) : buf_(buf) {}
+    TableKeyComparator(const TableKeyComparator &other) : buf_(other.buf_) {}
+    bool operator()(const Offset<T> &a, const Offset<T> &b) const {
+      auto table_a = reinterpret_cast<T *>(buf_.data_at(a.o));
+      auto table_b = reinterpret_cast<T *>(buf_.data_at(b.o));
+      return table_a->KeyCompareLessThan(table_b);
+    }
+    vector_downward &buf_;
+
+   private:
+    FLATBUFFERS_DELETE_FUNC(
+        TableKeyComparator &operator=(const TableKeyComparator &other));
+  };
+  /// @endcond
+
+  /// @brief Serialize an array of `table` offsets as a `vector` in the buffer
+  /// in sorted order.
+  /// @tparam T The data type that the offset refers to.
+  /// @param[in] v An array of type `Offset<T>` that contains the `table`
+  /// offsets to store in the buffer in sorted order.
+  /// @param[in] len The number of elements to store in the `vector`.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T>
+  Offset<Vector<Offset<T>>> CreateVectorOfSortedTables(Offset<T> *v,
+                                                       size_t len) {
+    std::sort(v, v + len, TableKeyComparator<T>(buf_));
+    return CreateVector(v, len);
+  }
+
+  /// @brief Serialize an array of `table` offsets as a `vector` in the buffer
+  /// in sorted order.
+  /// @tparam T The data type that the offset refers to.
+  /// @param[in] v An array of type `Offset<T>` that contains the `table`
+  /// offsets to store in the buffer in sorted order.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T, typename Alloc>
+  Offset<Vector<Offset<T>>> CreateVectorOfSortedTables(
+      std::vector<Offset<T>, Alloc> *v) {
+    return CreateVectorOfSortedTables(data(*v), v->size());
+  }
+
+  /// @brief Specialized version of `CreateVector` for non-copying use cases.
+  /// Write the data any time later to the returned buffer pointer `buf`.
+  /// @param[in] len The number of elements to store in the `vector`.
+  /// @param[in] elemsize The size of each element in the `vector`.
+  /// @param[out] buf A pointer to a `uint8_t` pointer that can be
+  /// written to at a later time to serialize the data into a `vector`
+  /// in the buffer.
+  uoffset_t CreateUninitializedVector(size_t len, size_t elemsize,
+                                      uint8_t **buf) {
+    NotNested();
+    StartVector(len, elemsize);
+    buf_.make_space(len * elemsize);
+    auto vec_start = GetSize();
+    auto vec_end = EndVector(len);
+    *buf = buf_.data_at(vec_start);
+    return vec_end;
+  }
+
+  /// @brief Specialized version of `CreateVector` for non-copying use cases.
+  /// Write the data any time later to the returned buffer pointer `buf`.
+  /// @tparam T The data type of the data that will be stored in the buffer
+  /// as a `vector`.
+  /// @param[in] len The number of elements to store in the `vector`.
+  /// @param[out] buf A pointer to a pointer of type `T` that can be
+  /// written to at a later time to serialize the data into a `vector`
+  /// in the buffer.
+  template<typename T>
+  Offset<Vector<T>> CreateUninitializedVector(size_t len, T **buf) {
+    AssertScalarT<T>();
+    return CreateUninitializedVector(len, sizeof(T),
+                                     reinterpret_cast<uint8_t **>(buf));
+  }
+
+  template<typename T>
+  Offset<Vector<const T *>> CreateUninitializedVectorOfStructs(size_t len,
+                                                               T **buf) {
+    return CreateUninitializedVector(len, sizeof(T),
+                                     reinterpret_cast<uint8_t **>(buf));
+  }
+
+  // @brief Create a vector of scalar type T given as input a vector of scalar
+  // type U, useful with e.g. pre "enum class" enums, or any existing scalar
+  // data of the wrong type.
+  template<typename T, typename U>
+  Offset<Vector<T>> CreateVectorScalarCast(const U *v, size_t len) {
+    AssertScalarT<T>();
+    AssertScalarT<U>();
+    StartVector(len, sizeof(T));
+    for (auto i = len; i > 0;) { PushElement(static_cast<T>(v[--i])); }
+    return Offset<Vector<T>>(EndVector(len));
+  }
+
+  /// @brief Write a struct by itself, typically to be part of a union.
+  template<typename T> Offset<const T *> CreateStruct(const T &structobj) {
+    NotNested();
+    Align(AlignOf<T>());
+    buf_.push_small(structobj);
+    return Offset<const T *>(GetSize());
+  }
+
+  /// @brief Finish serializing a buffer by writing the root offset.
+  /// @param[in] file_identifier If a `file_identifier` is given, the buffer
+  /// will be prefixed with a standard FlatBuffers file header.
+  template<typename T>
+  void Finish(Offset<T> root, const char *file_identifier = nullptr) {
+    Finish(root.o, file_identifier, false);
+  }
+
+  /// @brief Finish a buffer with a 32 bit size field pre-fixed (size of the
+  /// buffer following the size field). These buffers are NOT compatible
+  /// with standard buffers created by Finish, i.e. you can't call GetRoot
+  /// on them, you have to use GetSizePrefixedRoot instead.
+  /// All >32 bit quantities in this buffer will be aligned when the whole
+  /// size pre-fixed buffer is aligned.
+  /// These kinds of buffers are useful for creating a stream of FlatBuffers.
+  template<typename T>
+  void FinishSizePrefixed(Offset<T> root,
+                          const char *file_identifier = nullptr) {
+    Finish(root.o, file_identifier, true);
+  }
+
+  void SwapBufAllocator(FlatBufferBuilder &other) {
+    buf_.swap_allocator(other.buf_);
+  }
+
+ protected:
+  // You shouldn't really be copying instances of this class.
+  FlatBufferBuilder(const FlatBufferBuilder &);
+  FlatBufferBuilder &operator=(const FlatBufferBuilder &);
+
+  void Finish(uoffset_t root, const char *file_identifier, bool size_prefix) {
+    NotNested();
+    buf_.clear_scratch();
+    // This will cause the whole buffer to be aligned.
+    PreAlign((size_prefix ? sizeof(uoffset_t) : 0) + sizeof(uoffset_t) +
+                 (file_identifier ? kFileIdentifierLength : 0),
+             minalign_);
+    if (file_identifier) {
+      FLATBUFFERS_ASSERT(strlen(file_identifier) == kFileIdentifierLength);
+      PushBytes(reinterpret_cast<const uint8_t *>(file_identifier),
+                kFileIdentifierLength);
+    }
+    PushElement(ReferTo(root));  // Location of root.
+    if (size_prefix) { PushElement(GetSize()); }
+    finished = true;
+  }
+
+  struct FieldLoc {
+    uoffset_t off;
+    voffset_t id;
+  };
+
+  vector_downward buf_;
+
+  // Accumulating offsets of table members while it is being built.
+  // We store these in the scratch pad of buf_, after the vtable offsets.
+  uoffset_t num_field_loc;
+  // Track how much of the vtable is in use, so we can output the most compact
+  // possible vtable.
+  voffset_t max_voffset_;
+
+  // Ensure objects are not nested.
+  bool nested;
+
+  // Ensure the buffer is finished before it is being accessed.
+  bool finished;
+
+  size_t minalign_;
+
+  bool force_defaults_;  // Serialize values equal to their defaults anyway.
+
+  bool dedup_vtables_;
+
+  struct StringOffsetCompare {
+    StringOffsetCompare(const vector_downward &buf) : buf_(&buf) {}
+    bool operator()(const Offset<String> &a, const Offset<String> &b) const {
+      auto stra = reinterpret_cast<const String *>(buf_->data_at(a.o));
+      auto strb = reinterpret_cast<const String *>(buf_->data_at(b.o));
+      return StringLessThan(stra->data(), stra->size(), strb->data(),
+                            strb->size());
+    }
+    const vector_downward *buf_;
+  };
+
+  // For use with CreateSharedString. Instantiated on first use only.
+  typedef std::set<Offset<String>, StringOffsetCompare> StringOffsetMap;
+  StringOffsetMap *string_pool;
+
+ private:
+  // Allocates space for a vector of structures.
+  // Must be completed with EndVectorOfStructs().
+  template<typename T> T *StartVectorOfStructs(size_t vector_size) {
+    StartVector(vector_size * sizeof(T) / AlignOf<T>(), AlignOf<T>());
+    return reinterpret_cast<T *>(buf_.make_space(vector_size * sizeof(T)));
+  }
+
+  // End the vector of structures in the flatbuffers.
+  // Vector should have previously be started with StartVectorOfStructs().
+  template<typename T>
+  Offset<Vector<const T *>> EndVectorOfStructs(size_t vector_size) {
+    return Offset<Vector<const T *>>(EndVector(vector_size));
+  }
+};
+/// @}
+
+/// Helpers to get a typed pointer to objects that are currently being built.
+/// @warning Creating new objects will lead to reallocations and invalidates
+/// the pointer!
+template<typename T>
+T *GetMutableTemporaryPointer(FlatBufferBuilder &fbb, Offset<T> offset) {
+  return reinterpret_cast<T *>(fbb.GetCurrentBufferPointer() + fbb.GetSize() -
+                               offset.o);
+}
+
+template<typename T>
+const T *GetTemporaryPointer(FlatBufferBuilder &fbb, Offset<T> offset) {
+  return GetMutableTemporaryPointer<T>(fbb, offset);
+}
+
+template<typename T>
+void FlatBufferBuilder::Required(Offset<T> table, voffset_t field) {
+  auto table_ptr = reinterpret_cast<const Table *>(buf_.data_at(table.o));
+  bool ok = table_ptr->GetOptionalFieldOffset(field) != 0;
+  // If this fails, the caller will show what field needs to be set.
+  FLATBUFFERS_ASSERT(ok);
+  (void)ok;
+}
+
+}  // namespace flatbuffers
+
+#endif  // FLATBUFFERS_VECTOR_DOWNWARD_H_
\ No newline at end of file
diff --git a/include/flatbuffers/flatbuffers.h b/include/flatbuffers/flatbuffers.h
index fe87e876..509edd89 100644
--- a/include/flatbuffers/flatbuffers.h
+++ b/include/flatbuffers/flatbuffers.h
@@ -17,2803 +17,23 @@
 #ifndef FLATBUFFERS_H_
 #define FLATBUFFERS_H_
 
+// TODO: These includes are for mitigating the pains of users editing their
+// source because they relied on flatbuffers.h to include everything for them.
+#include "flatbuffers/array.h"
 #include "flatbuffers/base.h"
+#include "flatbuffers/buffer.h"
+#include "flatbuffers/buffer_ref.h"
+#include "flatbuffers/detached_buffer.h"
+#include "flatbuffers/flatbuffer_builder.h"
 #include "flatbuffers/stl_emulation.h"
-
-#ifndef FLATBUFFERS_CPP98_STL
-#  include <functional>
-#endif
-
-#if defined(FLATBUFFERS_NAN_DEFAULTS)
-#  include <cmath>
-#endif
+#include "flatbuffers/string.h"
+#include "flatbuffers/struct.h"
+#include "flatbuffers/table.h"
+#include "flatbuffers/vector.h"
+#include "flatbuffers/vector_downward.h"
+#include "flatbuffers/verifier.h"
 
 namespace flatbuffers {
-// Generic 'operator==' with conditional specialisations.
-// T e - new value of a scalar field.
-// T def - default of scalar (is known at compile-time).
-template<typename T> inline bool IsTheSameAs(T e, T def) { return e == def; }
-
-#if defined(FLATBUFFERS_NAN_DEFAULTS) && \
-    defined(FLATBUFFERS_HAS_NEW_STRTOD) && (FLATBUFFERS_HAS_NEW_STRTOD > 0)
-// Like `operator==(e, def)` with weak NaN if T=(float|double).
-template<typename T> inline bool IsFloatTheSameAs(T e, T def) {
-  return (e == def) || ((def != def) && (e != e));
-}
-template<> inline bool IsTheSameAs<float>(float e, float def) {
-  return IsFloatTheSameAs(e, def);
-}
-template<> inline bool IsTheSameAs<double>(double e, double def) {
-  return IsFloatTheSameAs(e, def);
-}
-#endif
-
-// Check 'v' is out of closed range [low; high].
-// Workaround for GCC warning [-Werror=type-limits]:
-// comparison is always true due to limited range of data type.
-template<typename T>
-inline bool IsOutRange(const T &v, const T &low, const T &high) {
-  return (v < low) || (high < v);
-}
-
-// Check 'v' is in closed range [low; high].
-template<typename T>
-inline bool IsInRange(const T &v, const T &low, const T &high) {
-  return !IsOutRange(v, low, high);
-}
-
-// Wrapper for uoffset_t to allow safe template specialization.
-// Value is allowed to be 0 to indicate a null object (see e.g. AddOffset).
-template<typename T> struct Offset {
-  uoffset_t o;
-  Offset() : o(0) {}
-  Offset(uoffset_t _o) : o(_o) {}
-  Offset<void> Union() const { return Offset<void>(o); }
-  bool IsNull() const { return !o; }
-};
-
-inline void EndianCheck() {
-  int endiantest = 1;
-  // If this fails, see FLATBUFFERS_LITTLEENDIAN above.
-  FLATBUFFERS_ASSERT(*reinterpret_cast<char *>(&endiantest) ==
-                     FLATBUFFERS_LITTLEENDIAN);
-  (void)endiantest;
-}
-
-template<typename T> FLATBUFFERS_CONSTEXPR size_t AlignOf() {
-  // clang-format off
-  #ifdef _MSC_VER
-    return __alignof(T);
-  #else
-    #ifndef alignof
-      return __alignof__(T);
-    #else
-      return alignof(T);
-    #endif
-  #endif
-  // clang-format on
-}
-
-// When we read serialized data from memory, in the case of most scalars,
-// we want to just read T, but in the case of Offset, we want to actually
-// perform the indirection and return a pointer.
-// The template specialization below does just that.
-// It is wrapped in a struct since function templates can't overload on the
-// return type like this.
-// The typedef is for the convenience of callers of this function
-// (avoiding the need for a trailing return decltype)
-template<typename T> struct IndirectHelper {
-  typedef T return_type;
-  typedef T mutable_return_type;
-  static const size_t element_stride = sizeof(T);
-  static return_type Read(const uint8_t *p, uoffset_t i) {
-    return EndianScalar((reinterpret_cast<const T *>(p))[i]);
-  }
-};
-template<typename T> struct IndirectHelper<Offset<T>> {
-  typedef const T *return_type;
-  typedef T *mutable_return_type;
-  static const size_t element_stride = sizeof(uoffset_t);
-  static return_type Read(const uint8_t *p, uoffset_t i) {
-    p += i * sizeof(uoffset_t);
-    return reinterpret_cast<return_type>(p + ReadScalar<uoffset_t>(p));
-  }
-};
-template<typename T> struct IndirectHelper<const T *> {
-  typedef const T *return_type;
-  typedef T *mutable_return_type;
-  static const size_t element_stride = sizeof(T);
-  static return_type Read(const uint8_t *p, uoffset_t i) {
-    return reinterpret_cast<const T *>(p + i * sizeof(T));
-  }
-};
-
-// An STL compatible iterator implementation for Vector below, effectively
-// calling Get() for every element.
-template<typename T, typename IT> struct VectorIterator {
-  typedef std::random_access_iterator_tag iterator_category;
-  typedef IT value_type;
-  typedef ptrdiff_t difference_type;
-  typedef IT *pointer;
-  typedef IT &reference;
-
-  VectorIterator(const uint8_t *data, uoffset_t i)
-      : data_(data + IndirectHelper<T>::element_stride * i) {}
-  VectorIterator(const VectorIterator &other) : data_(other.data_) {}
-  VectorIterator() : data_(nullptr) {}
-
-  VectorIterator &operator=(const VectorIterator &other) {
-    data_ = other.data_;
-    return *this;
-  }
-
-  // clang-format off
-  #if !defined(FLATBUFFERS_CPP98_STL)
-  VectorIterator &operator=(VectorIterator &&other) {
-    data_ = other.data_;
-    return *this;
-  }
-  #endif  // !defined(FLATBUFFERS_CPP98_STL)
-  // clang-format on
-
-  bool operator==(const VectorIterator &other) const {
-    return data_ == other.data_;
-  }
-
-  bool operator<(const VectorIterator &other) const {
-    return data_ < other.data_;
-  }
-
-  bool operator!=(const VectorIterator &other) const {
-    return data_ != other.data_;
-  }
-
-  difference_type operator-(const VectorIterator &other) const {
-    return (data_ - other.data_) / IndirectHelper<T>::element_stride;
-  }
-
-  // Note: return type is incompatible with the standard
-  // `reference operator*()`.
-  IT operator*() const { return IndirectHelper<T>::Read(data_, 0); }
-
-  // Note: return type is incompatible with the standard
-  // `pointer operator->()`.
-  IT operator->() const { return IndirectHelper<T>::Read(data_, 0); }
-
-  VectorIterator &operator++() {
-    data_ += IndirectHelper<T>::element_stride;
-    return *this;
-  }
-
-  VectorIterator operator++(int) {
-    VectorIterator temp(data_, 0);
-    data_ += IndirectHelper<T>::element_stride;
-    return temp;
-  }
-
-  VectorIterator operator+(const uoffset_t &offset) const {
-    return VectorIterator(data_ + offset * IndirectHelper<T>::element_stride,
-                          0);
-  }
-
-  VectorIterator &operator+=(const uoffset_t &offset) {
-    data_ += offset * IndirectHelper<T>::element_stride;
-    return *this;
-  }
-
-  VectorIterator &operator--() {
-    data_ -= IndirectHelper<T>::element_stride;
-    return *this;
-  }
-
-  VectorIterator operator--(int) {
-    VectorIterator temp(data_, 0);
-    data_ -= IndirectHelper<T>::element_stride;
-    return temp;
-  }
-
-  VectorIterator operator-(const uoffset_t &offset) const {
-    return VectorIterator(data_ - offset * IndirectHelper<T>::element_stride,
-                          0);
-  }
-
-  VectorIterator &operator-=(const uoffset_t &offset) {
-    data_ -= offset * IndirectHelper<T>::element_stride;
-    return *this;
-  }
-
- private:
-  const uint8_t *data_;
-};
-
-template<typename Iterator>
-struct VectorReverseIterator : public std::reverse_iterator<Iterator> {
-  explicit VectorReverseIterator(Iterator iter)
-      : std::reverse_iterator<Iterator>(iter) {}
-
-  // Note: return type is incompatible with the standard
-  // `reference operator*()`.
-  typename Iterator::value_type operator*() const {
-    auto tmp = std::reverse_iterator<Iterator>::current;
-    return *--tmp;
-  }
-
-  // Note: return type is incompatible with the standard
-  // `pointer operator->()`.
-  typename Iterator::value_type operator->() const {
-    auto tmp = std::reverse_iterator<Iterator>::current;
-    return *--tmp;
-  }
-};
-
-struct String;
-
-// This is used as a helper type for accessing vectors.
-// Vector::data() assumes the vector elements start after the length field.
-template<typename T> class Vector {
- public:
-  typedef VectorIterator<T, typename IndirectHelper<T>::mutable_return_type>
-      iterator;
-  typedef VectorIterator<T, typename IndirectHelper<T>::return_type>
-      const_iterator;
-  typedef VectorReverseIterator<iterator> reverse_iterator;
-  typedef VectorReverseIterator<const_iterator> const_reverse_iterator;
-
-  typedef typename flatbuffers::bool_constant<flatbuffers::is_scalar<T>::value>
-      scalar_tag;
-
-  static FLATBUFFERS_CONSTEXPR bool is_span_observable =
-      scalar_tag::value && (FLATBUFFERS_LITTLEENDIAN || sizeof(T) == 1);
-
-  uoffset_t size() const { return EndianScalar(length_); }
-
-  // Deprecated: use size(). Here for backwards compatibility.
-  FLATBUFFERS_ATTRIBUTE(deprecated("use size() instead"))
-  uoffset_t Length() const { return size(); }
-
-  typedef typename IndirectHelper<T>::return_type return_type;
-  typedef typename IndirectHelper<T>::mutable_return_type mutable_return_type;
-  typedef return_type value_type;
-
-  return_type Get(uoffset_t i) const {
-    FLATBUFFERS_ASSERT(i < size());
-    return IndirectHelper<T>::Read(Data(), i);
-  }
-
-  return_type operator[](uoffset_t i) const { return Get(i); }
-
-  // If this is a Vector of enums, T will be its storage type, not the enum
-  // type. This function makes it convenient to retrieve value with enum
-  // type E.
-  template<typename E> E GetEnum(uoffset_t i) const {
-    return static_cast<E>(Get(i));
-  }
-
-  // If this a vector of unions, this does the cast for you. There's no check
-  // to make sure this is the right type!
-  template<typename U> const U *GetAs(uoffset_t i) const {
-    return reinterpret_cast<const U *>(Get(i));
-  }
-
-  // If this a vector of unions, this does the cast for you. There's no check
-  // to make sure this is actually a string!
-  const String *GetAsString(uoffset_t i) const {
-    return reinterpret_cast<const String *>(Get(i));
-  }
-
-  const void *GetStructFromOffset(size_t o) const {
-    return reinterpret_cast<const void *>(Data() + o);
-  }
-
-  iterator begin() { return iterator(Data(), 0); }
-  const_iterator begin() const { return const_iterator(Data(), 0); }
-
-  iterator end() { return iterator(Data(), size()); }
-  const_iterator end() const { return const_iterator(Data(), size()); }
-
-  reverse_iterator rbegin() { return reverse_iterator(end()); }
-  const_reverse_iterator rbegin() const {
-    return const_reverse_iterator(end());
-  }
-
-  reverse_iterator rend() { return reverse_iterator(begin()); }
-  const_reverse_iterator rend() const {
-    return const_reverse_iterator(begin());
-  }
-
-  const_iterator cbegin() const { return begin(); }
-
-  const_iterator cend() const { return end(); }
-
-  const_reverse_iterator crbegin() const { return rbegin(); }
-
-  const_reverse_iterator crend() const { return rend(); }
-
-  // Change elements if you have a non-const pointer to this object.
-  // Scalars only. See reflection.h, and the documentation.
-  void Mutate(uoffset_t i, const T &val) {
-    FLATBUFFERS_ASSERT(i < size());
-    WriteScalar(data() + i, val);
-  }
-
-  // Change an element of a vector of tables (or strings).
-  // "val" points to the new table/string, as you can obtain from
-  // e.g. reflection::AddFlatBuffer().
-  void MutateOffset(uoffset_t i, const uint8_t *val) {
-    FLATBUFFERS_ASSERT(i < size());
-    static_assert(sizeof(T) == sizeof(uoffset_t), "Unrelated types");
-    WriteScalar(data() + i,
-                static_cast<uoffset_t>(val - (Data() + i * sizeof(uoffset_t))));
-  }
-
-  // Get a mutable pointer to tables/strings inside this vector.
-  mutable_return_type GetMutableObject(uoffset_t i) const {
-    FLATBUFFERS_ASSERT(i < size());
-    return const_cast<mutable_return_type>(IndirectHelper<T>::Read(Data(), i));
-  }
-
-  // The raw data in little endian format. Use with care.
-  const uint8_t *Data() const {
-    return reinterpret_cast<const uint8_t *>(&length_ + 1);
-  }
-
-  uint8_t *Data() { return reinterpret_cast<uint8_t *>(&length_ + 1); }
-
-  // Similarly, but typed, much like std::vector::data
-  const T *data() const { return reinterpret_cast<const T *>(Data()); }
-  T *data() { return reinterpret_cast<T *>(Data()); }
-
-  template<typename K> return_type LookupByKey(K key) const {
-    void *search_result = std::bsearch(
-        &key, Data(), size(), IndirectHelper<T>::element_stride, KeyCompare<K>);
-
-    if (!search_result) {
-      return nullptr;  // Key not found.
-    }
-
-    const uint8_t *element = reinterpret_cast<const uint8_t *>(search_result);
-
-    return IndirectHelper<T>::Read(element, 0);
-  }
-
-  template<typename K> mutable_return_type MutableLookupByKey(K key) {
-    return const_cast<mutable_return_type>(LookupByKey(key));
-  }
-
- protected:
-  // This class is only used to access pre-existing data. Don't ever
-  // try to construct these manually.
-  Vector();
-
-  uoffset_t length_;
-
- private:
-  // This class is a pointer. Copying will therefore create an invalid object.
-  // Private and unimplemented copy constructor.
-  Vector(const Vector &);
-  Vector &operator=(const Vector &);
-
-  template<typename K> static int KeyCompare(const void *ap, const void *bp) {
-    const K *key = reinterpret_cast<const K *>(ap);
-    const uint8_t *data = reinterpret_cast<const uint8_t *>(bp);
-    auto table = IndirectHelper<T>::Read(data, 0);
-
-    // std::bsearch compares with the operands transposed, so we negate the
-    // result here.
-    return -table->KeyCompareWithValue(*key);
-  }
-};
-
-template<class U>
-FLATBUFFERS_CONSTEXPR_CPP11 flatbuffers::span<U> make_span(Vector<U> &vec)
-    FLATBUFFERS_NOEXCEPT {
-  static_assert(Vector<U>::is_span_observable,
-                "wrong type U, only LE-scalar, or byte types are allowed");
-  return span<U>(vec.data(), vec.size());
-}
-
-template<class U>
-FLATBUFFERS_CONSTEXPR_CPP11 flatbuffers::span<const U> make_span(
-    const Vector<U> &vec) FLATBUFFERS_NOEXCEPT {
-  static_assert(Vector<U>::is_span_observable,
-                "wrong type U, only LE-scalar, or byte types are allowed");
-  return span<const U>(vec.data(), vec.size());
-}
-
-template<class U>
-FLATBUFFERS_CONSTEXPR_CPP11 flatbuffers::span<uint8_t> make_bytes_span(
-    Vector<U> &vec) FLATBUFFERS_NOEXCEPT {
-  static_assert(Vector<U>::scalar_tag::value,
-                "wrong type U, only LE-scalar, or byte types are allowed");
-  return span<uint8_t>(vec.Data(), vec.size() * sizeof(U));
-}
-
-template<class U>
-FLATBUFFERS_CONSTEXPR_CPP11 flatbuffers::span<const uint8_t> make_bytes_span(
-    const Vector<U> &vec) FLATBUFFERS_NOEXCEPT {
-  static_assert(Vector<U>::scalar_tag::value,
-                "wrong type U, only LE-scalar, or byte types are allowed");
-  return span<const uint8_t>(vec.Data(), vec.size() * sizeof(U));
-}
-
-// Represent a vector much like the template above, but in this case we
-// don't know what the element types are (used with reflection.h).
-class VectorOfAny {
- public:
-  uoffset_t size() const { return EndianScalar(length_); }
-
-  const uint8_t *Data() const {
-    return reinterpret_cast<const uint8_t *>(&length_ + 1);
-  }
-  uint8_t *Data() { return reinterpret_cast<uint8_t *>(&length_ + 1); }
-
- protected:
-  VectorOfAny();
-
-  uoffset_t length_;
-
- private:
-  VectorOfAny(const VectorOfAny &);
-  VectorOfAny &operator=(const VectorOfAny &);
-};
-
-#ifndef FLATBUFFERS_CPP98_STL
-template<typename T, typename U>
-Vector<Offset<T>> *VectorCast(Vector<Offset<U>> *ptr) {
-  static_assert(std::is_base_of<T, U>::value, "Unrelated types");
-  return reinterpret_cast<Vector<Offset<T>> *>(ptr);
-}
-
-template<typename T, typename U>
-const Vector<Offset<T>> *VectorCast(const Vector<Offset<U>> *ptr) {
-  static_assert(std::is_base_of<T, U>::value, "Unrelated types");
-  return reinterpret_cast<const Vector<Offset<T>> *>(ptr);
-}
-#endif
-
-// Convenient helper function to get the length of any vector, regardless
-// of whether it is null or not (the field is not set).
-template<typename T> static inline size_t VectorLength(const Vector<T> *v) {
-  return v ? v->size() : 0;
-}
-
-// This is used as a helper type for accessing arrays.
-template<typename T, uint16_t length> class Array {
-  // Array<T> can carry only POD data types (scalars or structs).
-  typedef typename flatbuffers::bool_constant<flatbuffers::is_scalar<T>::value>
-      scalar_tag;
-  typedef
-      typename flatbuffers::conditional<scalar_tag::value, T, const T *>::type
-          IndirectHelperType;
-
- public:
-  typedef uint16_t size_type;
-  typedef typename IndirectHelper<IndirectHelperType>::return_type return_type;
-  typedef VectorIterator<T, return_type> const_iterator;
-  typedef VectorReverseIterator<const_iterator> const_reverse_iterator;
-
-  // If T is a LE-scalar or a struct (!scalar_tag::value).
-  static FLATBUFFERS_CONSTEXPR bool is_span_observable =
-      (scalar_tag::value && (FLATBUFFERS_LITTLEENDIAN || sizeof(T) == 1)) ||
-      !scalar_tag::value;
-
-  FLATBUFFERS_CONSTEXPR uint16_t size() const { return length; }
-
-  return_type Get(uoffset_t i) const {
-    FLATBUFFERS_ASSERT(i < size());
-    return IndirectHelper<IndirectHelperType>::Read(Data(), i);
-  }
-
-  return_type operator[](uoffset_t i) const { return Get(i); }
-
-  // If this is a Vector of enums, T will be its storage type, not the enum
-  // type. This function makes it convenient to retrieve value with enum
-  // type E.
-  template<typename E> E GetEnum(uoffset_t i) const {
-    return static_cast<E>(Get(i));
-  }
-
-  const_iterator begin() const { return const_iterator(Data(), 0); }
-  const_iterator end() const { return const_iterator(Data(), size()); }
-
-  const_reverse_iterator rbegin() const {
-    return const_reverse_iterator(end());
-  }
-  const_reverse_iterator rend() const {
-    return const_reverse_iterator(begin());
-  }
-
-  const_iterator cbegin() const { return begin(); }
-  const_iterator cend() const { return end(); }
-
-  const_reverse_iterator crbegin() const { return rbegin(); }
-  const_reverse_iterator crend() const { return rend(); }
-
-  // Get a mutable pointer to elements inside this array.
-  // This method used to mutate arrays of structs followed by a @p Mutate
-  // operation. For primitive types use @p Mutate directly.
-  // @warning Assignments and reads to/from the dereferenced pointer are not
-  //  automatically converted to the correct endianness.
-  typename flatbuffers::conditional<scalar_tag::value, void, T *>::type
-  GetMutablePointer(uoffset_t i) const {
-    FLATBUFFERS_ASSERT(i < size());
-    return const_cast<T *>(&data()[i]);
-  }
-
-  // Change elements if you have a non-const pointer to this object.
-  void Mutate(uoffset_t i, const T &val) { MutateImpl(scalar_tag(), i, val); }
-
-  // The raw data in little endian format. Use with care.
-  const uint8_t *Data() const { return data_; }
-
-  uint8_t *Data() { return data_; }
-
-  // Similarly, but typed, much like std::vector::data
-  const T *data() const { return reinterpret_cast<const T *>(Data()); }
-  T *data() { return reinterpret_cast<T *>(Data()); }
-
-  // Copy data from a span with endian conversion.
-  // If this Array and the span overlap, the behavior is undefined.
-  void CopyFromSpan(flatbuffers::span<const T, length> src) {
-    const auto p1 = reinterpret_cast<const uint8_t *>(src.data());
-    const auto p2 = Data();
-    FLATBUFFERS_ASSERT(!(p1 >= p2 && p1 < (p2 + length)) &&
-                       !(p2 >= p1 && p2 < (p1 + length)));
-    (void)p1;
-    (void)p2;
-    CopyFromSpanImpl(flatbuffers::bool_constant<is_span_observable>(), src);
-  }
-
- protected:
-  void MutateImpl(flatbuffers::true_type, uoffset_t i, const T &val) {
-    FLATBUFFERS_ASSERT(i < size());
-    WriteScalar(data() + i, val);
-  }
-
-  void MutateImpl(flatbuffers::false_type, uoffset_t i, const T &val) {
-    *(GetMutablePointer(i)) = val;
-  }
-
-  void CopyFromSpanImpl(flatbuffers::true_type,
-                        flatbuffers::span<const T, length> src) {
-    // Use std::memcpy() instead of std::copy() to avoid performance degradation
-    // due to aliasing if T is char or unsigned char.
-    // The size is known at compile time, so memcpy would be inlined.
-    std::memcpy(data(), src.data(), length * sizeof(T));
-  }
-
-  // Copy data from flatbuffers::span with endian conversion.
-  void CopyFromSpanImpl(flatbuffers::false_type,
-                        flatbuffers::span<const T, length> src) {
-    for (size_type k = 0; k < length; k++) { Mutate(k, src[k]); }
-  }
-
-  // This class is only used to access pre-existing data. Don't ever
-  // try to construct these manually.
-  // 'constexpr' allows us to use 'size()' at compile time.
-  // @note Must not use 'FLATBUFFERS_CONSTEXPR' here, as const is not allowed on
-  //  a constructor.
-#if defined(__cpp_constexpr)
-  constexpr Array();
-#else
-  Array();
-#endif
-
-  uint8_t data_[length * sizeof(T)];
-
- private:
-  // This class is a pointer. Copying will therefore create an invalid object.
-  // Private and unimplemented copy constructor.
-  Array(const Array &);
-  Array &operator=(const Array &);
-};
-
-// Specialization for Array[struct] with access using Offset<void> pointer.
-// This specialization used by idl_gen_text.cpp.
-template<typename T, uint16_t length> class Array<Offset<T>, length> {
-  static_assert(flatbuffers::is_same<T, void>::value, "unexpected type T");
-
- public:
-  typedef const void *return_type;
-
-  const uint8_t *Data() const { return data_; }
-
-  // Make idl_gen_text.cpp::PrintContainer happy.
-  return_type operator[](uoffset_t) const {
-    FLATBUFFERS_ASSERT(false);
-    return nullptr;
-  }
-
- private:
-  // This class is only used to access pre-existing data.
-  Array();
-  Array(const Array &);
-  Array &operator=(const Array &);
-
-  uint8_t data_[1];
-};
-
-template<class U, uint16_t N>
-FLATBUFFERS_CONSTEXPR_CPP11 flatbuffers::span<U, N> make_span(Array<U, N> &arr)
-    FLATBUFFERS_NOEXCEPT {
-  static_assert(
-      Array<U, N>::is_span_observable,
-      "wrong type U, only plain struct, LE-scalar, or byte types are allowed");
-  return span<U, N>(arr.data(), N);
-}
-
-template<class U, uint16_t N>
-FLATBUFFERS_CONSTEXPR_CPP11 flatbuffers::span<const U, N> make_span(
-    const Array<U, N> &arr) FLATBUFFERS_NOEXCEPT {
-  static_assert(
-      Array<U, N>::is_span_observable,
-      "wrong type U, only plain struct, LE-scalar, or byte types are allowed");
-  return span<const U, N>(arr.data(), N);
-}
-
-template<class U, uint16_t N>
-FLATBUFFERS_CONSTEXPR_CPP11 flatbuffers::span<uint8_t, sizeof(U) * N>
-make_bytes_span(Array<U, N> &arr) FLATBUFFERS_NOEXCEPT {
-  static_assert(Array<U, N>::is_span_observable,
-                "internal error, Array<T> might hold only scalars or structs");
-  return span<uint8_t, sizeof(U) * N>(arr.Data(), sizeof(U) * N);
-}
-
-template<class U, uint16_t N>
-FLATBUFFERS_CONSTEXPR_CPP11 flatbuffers::span<const uint8_t, sizeof(U) * N>
-make_bytes_span(const Array<U, N> &arr) FLATBUFFERS_NOEXCEPT {
-  static_assert(Array<U, N>::is_span_observable,
-                "internal error, Array<T> might hold only scalars or structs");
-  return span<const uint8_t, sizeof(U) * N>(arr.Data(), sizeof(U) * N);
-}
-
-// Cast a raw T[length] to a raw flatbuffers::Array<T, length>
-// without endian conversion. Use with care.
-// TODO: move these Cast-methods to `internal` namespace.
-template<typename T, uint16_t length>
-Array<T, length> &CastToArray(T (&arr)[length]) {
-  return *reinterpret_cast<Array<T, length> *>(arr);
-}
-
-template<typename T, uint16_t length>
-const Array<T, length> &CastToArray(const T (&arr)[length]) {
-  return *reinterpret_cast<const Array<T, length> *>(arr);
-}
-
-template<typename E, typename T, uint16_t length>
-Array<E, length> &CastToArrayOfEnum(T (&arr)[length]) {
-  static_assert(sizeof(E) == sizeof(T), "invalid enum type E");
-  return *reinterpret_cast<Array<E, length> *>(arr);
-}
-
-template<typename E, typename T, uint16_t length>
-const Array<E, length> &CastToArrayOfEnum(const T (&arr)[length]) {
-  static_assert(sizeof(E) == sizeof(T), "invalid enum type E");
-  return *reinterpret_cast<const Array<E, length> *>(arr);
-}
-
-// Lexicographically compare two strings (possibly containing nulls), and
-// return true if the first is less than the second.
-static inline bool StringLessThan(const char *a_data, uoffset_t a_size,
-                                  const char *b_data, uoffset_t b_size) {
-  const auto cmp = memcmp(a_data, b_data, (std::min)(a_size, b_size));
-  return cmp == 0 ? a_size < b_size : cmp < 0;
-}
-
-struct String : public Vector<char> {
-  const char *c_str() const { return reinterpret_cast<const char *>(Data()); }
-  std::string str() const { return std::string(c_str(), size()); }
-
-  // clang-format off
-  #ifdef FLATBUFFERS_HAS_STRING_VIEW
-  flatbuffers::string_view string_view() const {
-    return flatbuffers::string_view(c_str(), size());
-  }
-  #endif // FLATBUFFERS_HAS_STRING_VIEW
-  // clang-format on
-
-  bool operator<(const String &o) const {
-    return StringLessThan(this->data(), this->size(), o.data(), o.size());
-  }
-};
-
-// Convenience function to get std::string from a String returning an empty
-// string on null pointer.
-static inline std::string GetString(const String *str) {
-  return str ? str->str() : "";
-}
-
-// Convenience function to get char* from a String returning an empty string on
-// null pointer.
-static inline const char *GetCstring(const String *str) {
-  return str ? str->c_str() : "";
-}
-
-#ifdef FLATBUFFERS_HAS_STRING_VIEW
-// Convenience function to get string_view from a String returning an empty
-// string_view on null pointer.
-static inline flatbuffers::string_view GetStringView(const String *str) {
-  return str ? str->string_view() : flatbuffers::string_view();
-}
-#endif  // FLATBUFFERS_HAS_STRING_VIEW
-
-// Allocator interface. This is flatbuffers-specific and meant only for
-// `vector_downward` usage.
-class Allocator {
- public:
-  virtual ~Allocator() {}
-
-  // Allocate `size` bytes of memory.
-  virtual uint8_t *allocate(size_t size) = 0;
-
-  // Deallocate `size` bytes of memory at `p` allocated by this allocator.
-  virtual void deallocate(uint8_t *p, size_t size) = 0;
-
-  // Reallocate `new_size` bytes of memory, replacing the old region of size
-  // `old_size` at `p`. In contrast to a normal realloc, this grows downwards,
-  // and is intended specifcally for `vector_downward` use.
-  // `in_use_back` and `in_use_front` indicate how much of `old_size` is
-  // actually in use at each end, and needs to be copied.
-  virtual uint8_t *reallocate_downward(uint8_t *old_p, size_t old_size,
-                                       size_t new_size, size_t in_use_back,
-                                       size_t in_use_front) {
-    FLATBUFFERS_ASSERT(new_size > old_size);  // vector_downward only grows
-    uint8_t *new_p = allocate(new_size);
-    memcpy_downward(old_p, old_size, new_p, new_size, in_use_back,
-                    in_use_front);
-    deallocate(old_p, old_size);
-    return new_p;
-  }
-
- protected:
-  // Called by `reallocate_downward` to copy memory from `old_p` of `old_size`
-  // to `new_p` of `new_size`. Only memory of size `in_use_front` and
-  // `in_use_back` will be copied from the front and back of the old memory
-  // allocation.
-  void memcpy_downward(uint8_t *old_p, size_t old_size, uint8_t *new_p,
-                       size_t new_size, size_t in_use_back,
-                       size_t in_use_front) {
-    memcpy(new_p + new_size - in_use_back, old_p + old_size - in_use_back,
-           in_use_back);
-    memcpy(new_p, old_p, in_use_front);
-  }
-};
-
-// DefaultAllocator uses new/delete to allocate memory regions
-class DefaultAllocator : public Allocator {
- public:
-  uint8_t *allocate(size_t size) FLATBUFFERS_OVERRIDE {
-    return new uint8_t[size];
-  }
-
-  void deallocate(uint8_t *p, size_t) FLATBUFFERS_OVERRIDE { delete[] p; }
-
-  static void dealloc(void *p, size_t) { delete[] static_cast<uint8_t *>(p); }
-};
-
-// These functions allow for a null allocator to mean use the default allocator,
-// as used by DetachedBuffer and vector_downward below.
-// This is to avoid having a statically or dynamically allocated default
-// allocator, or having to move it between the classes that may own it.
-inline uint8_t *Allocate(Allocator *allocator, size_t size) {
-  return allocator ? allocator->allocate(size)
-                   : DefaultAllocator().allocate(size);
-}
-
-inline void Deallocate(Allocator *allocator, uint8_t *p, size_t size) {
-  if (allocator)
-    allocator->deallocate(p, size);
-  else
-    DefaultAllocator().deallocate(p, size);
-}
-
-inline uint8_t *ReallocateDownward(Allocator *allocator, uint8_t *old_p,
-                                   size_t old_size, size_t new_size,
-                                   size_t in_use_back, size_t in_use_front) {
-  return allocator ? allocator->reallocate_downward(old_p, old_size, new_size,
-                                                    in_use_back, in_use_front)
-                   : DefaultAllocator().reallocate_downward(
-                         old_p, old_size, new_size, in_use_back, in_use_front);
-}
-
-// DetachedBuffer is a finished flatbuffer memory region, detached from its
-// builder. The original memory region and allocator are also stored so that
-// the DetachedBuffer can manage the memory lifetime.
-class DetachedBuffer {
- public:
-  DetachedBuffer()
-      : allocator_(nullptr),
-        own_allocator_(false),
-        buf_(nullptr),
-        reserved_(0),
-        cur_(nullptr),
-        size_(0) {}
-
-  DetachedBuffer(Allocator *allocator, bool own_allocator, uint8_t *buf,
-                 size_t reserved, uint8_t *cur, size_t sz)
-      : allocator_(allocator),
-        own_allocator_(own_allocator),
-        buf_(buf),
-        reserved_(reserved),
-        cur_(cur),
-        size_(sz) {}
-
-  // clang-format off
-  #if !defined(FLATBUFFERS_CPP98_STL)
-  // clang-format on
-  DetachedBuffer(DetachedBuffer &&other)
-      : allocator_(other.allocator_),
-        own_allocator_(other.own_allocator_),
-        buf_(other.buf_),
-        reserved_(other.reserved_),
-        cur_(other.cur_),
-        size_(other.size_) {
-    other.reset();
-  }
-  // clang-format off
-  #endif  // !defined(FLATBUFFERS_CPP98_STL)
-  // clang-format on
-
-  // clang-format off
-  #if !defined(FLATBUFFERS_CPP98_STL)
-  // clang-format on
-  DetachedBuffer &operator=(DetachedBuffer &&other) {
-    if (this == &other) return *this;
-
-    destroy();
-
-    allocator_ = other.allocator_;
-    own_allocator_ = other.own_allocator_;
-    buf_ = other.buf_;
-    reserved_ = other.reserved_;
-    cur_ = other.cur_;
-    size_ = other.size_;
-
-    other.reset();
-
-    return *this;
-  }
-  // clang-format off
-  #endif  // !defined(FLATBUFFERS_CPP98_STL)
-  // clang-format on
-
-  ~DetachedBuffer() { destroy(); }
-
-  const uint8_t *data() const { return cur_; }
-
-  uint8_t *data() { return cur_; }
-
-  size_t size() const { return size_; }
-
-  // clang-format off
-  #if 0  // disabled for now due to the ordering of classes in this header
-  template <class T>
-  bool Verify() const {
-    Verifier verifier(data(), size());
-    return verifier.Verify<T>(nullptr);
-  }
-
-  template <class T>
-  const T* GetRoot() const {
-    return flatbuffers::GetRoot<T>(data());
-  }
-
-  template <class T>
-  T* GetRoot() {
-    return flatbuffers::GetRoot<T>(data());
-  }
-  #endif
-  // clang-format on
-
-  // clang-format off
-  #if !defined(FLATBUFFERS_CPP98_STL)
-  // clang-format on
-  // These may change access mode, leave these at end of public section
-  FLATBUFFERS_DELETE_FUNC(DetachedBuffer(const DetachedBuffer &other));
-  FLATBUFFERS_DELETE_FUNC(
-      DetachedBuffer &operator=(const DetachedBuffer &other));
-  // clang-format off
-  #endif  // !defined(FLATBUFFERS_CPP98_STL)
-  // clang-format on
-
- protected:
-  Allocator *allocator_;
-  bool own_allocator_;
-  uint8_t *buf_;
-  size_t reserved_;
-  uint8_t *cur_;
-  size_t size_;
-
-  inline void destroy() {
-    if (buf_) Deallocate(allocator_, buf_, reserved_);
-    if (own_allocator_ && allocator_) { delete allocator_; }
-    reset();
-  }
-
-  inline void reset() {
-    allocator_ = nullptr;
-    own_allocator_ = false;
-    buf_ = nullptr;
-    reserved_ = 0;
-    cur_ = nullptr;
-    size_ = 0;
-  }
-};
-
-// This is a minimal replication of std::vector<uint8_t> functionality,
-// except growing from higher to lower addresses. i.e push_back() inserts data
-// in the lowest address in the vector.
-// Since this vector leaves the lower part unused, we support a "scratch-pad"
-// that can be stored there for temporary data, to share the allocated space.
-// Essentially, this supports 2 std::vectors in a single buffer.
-class vector_downward {
- public:
-  explicit vector_downward(size_t initial_size, Allocator *allocator,
-                           bool own_allocator, size_t buffer_minalign)
-      : allocator_(allocator),
-        own_allocator_(own_allocator),
-        initial_size_(initial_size),
-        buffer_minalign_(buffer_minalign),
-        reserved_(0),
-        buf_(nullptr),
-        cur_(nullptr),
-        scratch_(nullptr) {}
-
-  // clang-format off
-  #if !defined(FLATBUFFERS_CPP98_STL)
-  vector_downward(vector_downward &&other)
-  #else
-  vector_downward(vector_downward &other)
-  #endif  // defined(FLATBUFFERS_CPP98_STL)
-      // clang-format on
-      : allocator_(other.allocator_),
-        own_allocator_(other.own_allocator_),
-        initial_size_(other.initial_size_),
-        buffer_minalign_(other.buffer_minalign_),
-        reserved_(other.reserved_),
-        buf_(other.buf_),
-        cur_(other.cur_),
-        scratch_(other.scratch_) {
-    // No change in other.allocator_
-    // No change in other.initial_size_
-    // No change in other.buffer_minalign_
-    other.own_allocator_ = false;
-    other.reserved_ = 0;
-    other.buf_ = nullptr;
-    other.cur_ = nullptr;
-    other.scratch_ = nullptr;
-  }
-
-  // clang-format off
-  #if !defined(FLATBUFFERS_CPP98_STL)
-  // clang-format on
-  vector_downward &operator=(vector_downward &&other) {
-    // Move construct a temporary and swap idiom
-    vector_downward temp(std::move(other));
-    swap(temp);
-    return *this;
-  }
-  // clang-format off
-  #endif  // defined(FLATBUFFERS_CPP98_STL)
-  // clang-format on
-
-  ~vector_downward() {
-    clear_buffer();
-    clear_allocator();
-  }
-
-  void reset() {
-    clear_buffer();
-    clear();
-  }
-
-  void clear() {
-    if (buf_) {
-      cur_ = buf_ + reserved_;
-    } else {
-      reserved_ = 0;
-      cur_ = nullptr;
-    }
-    clear_scratch();
-  }
-
-  void clear_scratch() { scratch_ = buf_; }
-
-  void clear_allocator() {
-    if (own_allocator_ && allocator_) { delete allocator_; }
-    allocator_ = nullptr;
-    own_allocator_ = false;
-  }
-
-  void clear_buffer() {
-    if (buf_) Deallocate(allocator_, buf_, reserved_);
-    buf_ = nullptr;
-  }
-
-  // Relinquish the pointer to the caller.
-  uint8_t *release_raw(size_t &allocated_bytes, size_t &offset) {
-    auto *buf = buf_;
-    allocated_bytes = reserved_;
-    offset = static_cast<size_t>(cur_ - buf_);
-
-    // release_raw only relinquishes the buffer ownership.
-    // Does not deallocate or reset the allocator. Destructor will do that.
-    buf_ = nullptr;
-    clear();
-    return buf;
-  }
-
-  // Relinquish the pointer to the caller.
-  DetachedBuffer release() {
-    // allocator ownership (if any) is transferred to DetachedBuffer.
-    DetachedBuffer fb(allocator_, own_allocator_, buf_, reserved_, cur_,
-                      size());
-    if (own_allocator_) {
-      allocator_ = nullptr;
-      own_allocator_ = false;
-    }
-    buf_ = nullptr;
-    clear();
-    return fb;
-  }
-
-  size_t ensure_space(size_t len) {
-    FLATBUFFERS_ASSERT(cur_ >= scratch_ && scratch_ >= buf_);
-    if (len > static_cast<size_t>(cur_ - scratch_)) { reallocate(len); }
-    // Beyond this, signed offsets may not have enough range:
-    // (FlatBuffers > 2GB not supported).
-    FLATBUFFERS_ASSERT(size() < FLATBUFFERS_MAX_BUFFER_SIZE);
-    return len;
-  }
-
-  inline uint8_t *make_space(size_t len) {
-    size_t space = ensure_space(len);
-    cur_ -= space;
-    return cur_;
-  }
-
-  // Returns nullptr if using the DefaultAllocator.
-  Allocator *get_custom_allocator() { return allocator_; }
-
-  uoffset_t size() const {
-    return static_cast<uoffset_t>(reserved_ - static_cast<size_t>(cur_ - buf_));
-  }
-
-  uoffset_t scratch_size() const {
-    return static_cast<uoffset_t>(scratch_ - buf_);
-  }
-
-  size_t capacity() const { return reserved_; }
-
-  uint8_t *data() const {
-    FLATBUFFERS_ASSERT(cur_);
-    return cur_;
-  }
-
-  uint8_t *scratch_data() const {
-    FLATBUFFERS_ASSERT(buf_);
-    return buf_;
-  }
-
-  uint8_t *scratch_end() const {
-    FLATBUFFERS_ASSERT(scratch_);
-    return scratch_;
-  }
-
-  uint8_t *data_at(size_t offset) const { return buf_ + reserved_ - offset; }
-
-  void push(const uint8_t *bytes, size_t num) {
-    if (num > 0) { memcpy(make_space(num), bytes, num); }
-  }
-
-  // Specialized version of push() that avoids memcpy call for small data.
-  template<typename T> void push_small(const T &little_endian_t) {
-    make_space(sizeof(T));
-    *reinterpret_cast<T *>(cur_) = little_endian_t;
-  }
-
-  template<typename T> void scratch_push_small(const T &t) {
-    ensure_space(sizeof(T));
-    *reinterpret_cast<T *>(scratch_) = t;
-    scratch_ += sizeof(T);
-  }
-
-  // fill() is most frequently called with small byte counts (<= 4),
-  // which is why we're using loops rather than calling memset.
-  void fill(size_t zero_pad_bytes) {
-    make_space(zero_pad_bytes);
-    for (size_t i = 0; i < zero_pad_bytes; i++) cur_[i] = 0;
-  }
-
-  // Version for when we know the size is larger.
-  // Precondition: zero_pad_bytes > 0
-  void fill_big(size_t zero_pad_bytes) {
-    memset(make_space(zero_pad_bytes), 0, zero_pad_bytes);
-  }
-
-  void pop(size_t bytes_to_remove) { cur_ += bytes_to_remove; }
-  void scratch_pop(size_t bytes_to_remove) { scratch_ -= bytes_to_remove; }
-
-  void swap(vector_downward &other) {
-    using std::swap;
-    swap(allocator_, other.allocator_);
-    swap(own_allocator_, other.own_allocator_);
-    swap(initial_size_, other.initial_size_);
-    swap(buffer_minalign_, other.buffer_minalign_);
-    swap(reserved_, other.reserved_);
-    swap(buf_, other.buf_);
-    swap(cur_, other.cur_);
-    swap(scratch_, other.scratch_);
-  }
-
-  void swap_allocator(vector_downward &other) {
-    using std::swap;
-    swap(allocator_, other.allocator_);
-    swap(own_allocator_, other.own_allocator_);
-  }
-
- private:
-  // You shouldn't really be copying instances of this class.
-  FLATBUFFERS_DELETE_FUNC(vector_downward(const vector_downward &));
-  FLATBUFFERS_DELETE_FUNC(vector_downward &operator=(const vector_downward &));
-
-  Allocator *allocator_;
-  bool own_allocator_;
-  size_t initial_size_;
-  size_t buffer_minalign_;
-  size_t reserved_;
-  uint8_t *buf_;
-  uint8_t *cur_;  // Points at location between empty (below) and used (above).
-  uint8_t *scratch_;  // Points to the end of the scratchpad in use.
-
-  void reallocate(size_t len) {
-    auto old_reserved = reserved_;
-    auto old_size = size();
-    auto old_scratch_size = scratch_size();
-    reserved_ +=
-        (std::max)(len, old_reserved ? old_reserved / 2 : initial_size_);
-    reserved_ = (reserved_ + buffer_minalign_ - 1) & ~(buffer_minalign_ - 1);
-    if (buf_) {
-      buf_ = ReallocateDownward(allocator_, buf_, old_reserved, reserved_,
-                                old_size, old_scratch_size);
-    } else {
-      buf_ = Allocate(allocator_, reserved_);
-    }
-    cur_ = buf_ + reserved_ - old_size;
-    scratch_ = buf_ + old_scratch_size;
-  }
-};
-
-// Converts a Field ID to a virtual table offset.
-inline voffset_t FieldIndexToOffset(voffset_t field_id) {
-  // Should correspond to what EndTable() below builds up.
-  const int fixed_fields = 2;  // Vtable size and Object Size.
-  return static_cast<voffset_t>((field_id + fixed_fields) * sizeof(voffset_t));
-}
-
-template<typename T, typename Alloc>
-const T *data(const std::vector<T, Alloc> &v) {
-  // Eventually the returned pointer gets passed down to memcpy, so
-  // we need it to be non-null to avoid undefined behavior.
-  static uint8_t t;
-  return v.empty() ? reinterpret_cast<const T *>(&t) : &v.front();
-}
-template<typename T, typename Alloc> T *data(std::vector<T, Alloc> &v) {
-  // Eventually the returned pointer gets passed down to memcpy, so
-  // we need it to be non-null to avoid undefined behavior.
-  static uint8_t t;
-  return v.empty() ? reinterpret_cast<T *>(&t) : &v.front();
-}
-
-/// @endcond
-
-/// @addtogroup flatbuffers_cpp_api
-/// @{
-/// @class FlatBufferBuilder
-/// @brief Helper class to hold data needed in creation of a FlatBuffer.
-/// To serialize data, you typically call one of the `Create*()` functions in
-/// the generated code, which in turn call a sequence of `StartTable`/
-/// `PushElement`/`AddElement`/`EndTable`, or the builtin `CreateString`/
-/// `CreateVector` functions. Do this is depth-first order to build up a tree to
-/// the root. `Finish()` wraps up the buffer ready for transport.
-class FlatBufferBuilder {
- public:
-  /// @brief Default constructor for FlatBufferBuilder.
-  /// @param[in] initial_size The initial size of the buffer, in bytes. Defaults
-  /// to `1024`.
-  /// @param[in] allocator An `Allocator` to use. If null will use
-  /// `DefaultAllocator`.
-  /// @param[in] own_allocator Whether the builder/vector should own the
-  /// allocator. Defaults to / `false`.
-  /// @param[in] buffer_minalign Force the buffer to be aligned to the given
-  /// minimum alignment upon reallocation. Only needed if you intend to store
-  /// types with custom alignment AND you wish to read the buffer in-place
-  /// directly after creation.
-  explicit FlatBufferBuilder(
-      size_t initial_size = 1024, Allocator *allocator = nullptr,
-      bool own_allocator = false,
-      size_t buffer_minalign = AlignOf<largest_scalar_t>())
-      : buf_(initial_size, allocator, own_allocator, buffer_minalign),
-        num_field_loc(0),
-        max_voffset_(0),
-        nested(false),
-        finished(false),
-        minalign_(1),
-        force_defaults_(false),
-        dedup_vtables_(true),
-        string_pool(nullptr) {
-    EndianCheck();
-  }
-
-  // clang-format off
-  /// @brief Move constructor for FlatBufferBuilder.
-  #if !defined(FLATBUFFERS_CPP98_STL)
-  FlatBufferBuilder(FlatBufferBuilder &&other)
-  #else
-  FlatBufferBuilder(FlatBufferBuilder &other)
-  #endif  // #if !defined(FLATBUFFERS_CPP98_STL)
-    : buf_(1024, nullptr, false, AlignOf<largest_scalar_t>()),
-      num_field_loc(0),
-      max_voffset_(0),
-      nested(false),
-      finished(false),
-      minalign_(1),
-      force_defaults_(false),
-      dedup_vtables_(true),
-      string_pool(nullptr) {
-    EndianCheck();
-    // Default construct and swap idiom.
-    // Lack of delegating constructors in vs2010 makes it more verbose than needed.
-    Swap(other);
-  }
-  // clang-format on
-
-  // clang-format off
-  #if !defined(FLATBUFFERS_CPP98_STL)
-  // clang-format on
-  /// @brief Move assignment operator for FlatBufferBuilder.
-  FlatBufferBuilder &operator=(FlatBufferBuilder &&other) {
-    // Move construct a temporary and swap idiom
-    FlatBufferBuilder temp(std::move(other));
-    Swap(temp);
-    return *this;
-  }
-  // clang-format off
-  #endif  // defined(FLATBUFFERS_CPP98_STL)
-  // clang-format on
-
-  void Swap(FlatBufferBuilder &other) {
-    using std::swap;
-    buf_.swap(other.buf_);
-    swap(num_field_loc, other.num_field_loc);
-    swap(max_voffset_, other.max_voffset_);
-    swap(nested, other.nested);
-    swap(finished, other.finished);
-    swap(minalign_, other.minalign_);
-    swap(force_defaults_, other.force_defaults_);
-    swap(dedup_vtables_, other.dedup_vtables_);
-    swap(string_pool, other.string_pool);
-  }
-
-  ~FlatBufferBuilder() {
-    if (string_pool) delete string_pool;
-  }
-
-  void Reset() {
-    Clear();       // clear builder state
-    buf_.reset();  // deallocate buffer
-  }
-
-  /// @brief Reset all the state in this FlatBufferBuilder so it can be reused
-  /// to construct another buffer.
-  void Clear() {
-    ClearOffsets();
-    buf_.clear();
-    nested = false;
-    finished = false;
-    minalign_ = 1;
-    if (string_pool) string_pool->clear();
-  }
-
-  /// @brief The current size of the serialized buffer, counting from the end.
-  /// @return Returns an `uoffset_t` with the current size of the buffer.
-  uoffset_t GetSize() const { return buf_.size(); }
-
-  /// @brief Get the serialized buffer (after you call `Finish()`).
-  /// @return Returns an `uint8_t` pointer to the FlatBuffer data inside the
-  /// buffer.
-  uint8_t *GetBufferPointer() const {
-    Finished();
-    return buf_.data();
-  }
-
-  /// @brief Get the serialized buffer (after you call `Finish()`) as a span.
-  /// @return Returns a constructed flatbuffers::span that is a view over the
-  /// FlatBuffer data inside the buffer.
-  flatbuffers::span<uint8_t> GetBufferSpan() const {
-    Finished();
-    return flatbuffers::span<uint8_t>(buf_.data(), buf_.size());
-  }
-
-  /// @brief Get a pointer to an unfinished buffer.
-  /// @return Returns a `uint8_t` pointer to the unfinished buffer.
-  uint8_t *GetCurrentBufferPointer() const { return buf_.data(); }
-
-  /// @brief Get the released pointer to the serialized buffer.
-  /// @warning Do NOT attempt to use this FlatBufferBuilder afterwards!
-  /// @return A `FlatBuffer` that owns the buffer and its allocator and
-  /// behaves similar to a `unique_ptr` with a deleter.
-  FLATBUFFERS_ATTRIBUTE(deprecated("use Release() instead"))
-  DetachedBuffer ReleaseBufferPointer() {
-    Finished();
-    return buf_.release();
-  }
-
-  /// @brief Get the released DetachedBuffer.
-  /// @return A `DetachedBuffer` that owns the buffer and its allocator.
-  DetachedBuffer Release() {
-    Finished();
-    return buf_.release();
-  }
-
-  /// @brief Get the released pointer to the serialized buffer.
-  /// @param size The size of the memory block containing
-  /// the serialized `FlatBuffer`.
-  /// @param offset The offset from the released pointer where the finished
-  /// `FlatBuffer` starts.
-  /// @return A raw pointer to the start of the memory block containing
-  /// the serialized `FlatBuffer`.
-  /// @remark If the allocator is owned, it gets deleted when the destructor is
-  /// called..
-  uint8_t *ReleaseRaw(size_t &size, size_t &offset) {
-    Finished();
-    return buf_.release_raw(size, offset);
-  }
-
-  /// @brief get the minimum alignment this buffer needs to be accessed
-  /// properly. This is only known once all elements have been written (after
-  /// you call Finish()). You can use this information if you need to embed
-  /// a FlatBuffer in some other buffer, such that you can later read it
-  /// without first having to copy it into its own buffer.
-  size_t GetBufferMinAlignment() const {
-    Finished();
-    return minalign_;
-  }
-
-  /// @cond FLATBUFFERS_INTERNAL
-  void Finished() const {
-    // If you get this assert, you're attempting to get access a buffer
-    // which hasn't been finished yet. Be sure to call
-    // FlatBufferBuilder::Finish with your root table.
-    // If you really need to access an unfinished buffer, call
-    // GetCurrentBufferPointer instead.
-    FLATBUFFERS_ASSERT(finished);
-  }
-  /// @endcond
-
-  /// @brief In order to save space, fields that are set to their default value
-  /// don't get serialized into the buffer.
-  /// @param[in] fd When set to `true`, always serializes default values that
-  /// are set. Optional fields which are not set explicitly, will still not be
-  /// serialized.
-  void ForceDefaults(bool fd) { force_defaults_ = fd; }
-
-  /// @brief By default vtables are deduped in order to save space.
-  /// @param[in] dedup When set to `true`, dedup vtables.
-  void DedupVtables(bool dedup) { dedup_vtables_ = dedup; }
-
-  /// @cond FLATBUFFERS_INTERNAL
-  void Pad(size_t num_bytes) { buf_.fill(num_bytes); }
-
-  void TrackMinAlign(size_t elem_size) {
-    if (elem_size > minalign_) minalign_ = elem_size;
-  }
-
-  void Align(size_t elem_size) {
-    TrackMinAlign(elem_size);
-    buf_.fill(PaddingBytes(buf_.size(), elem_size));
-  }
-
-  void PushFlatBuffer(const uint8_t *bytes, size_t size) {
-    PushBytes(bytes, size);
-    finished = true;
-  }
-
-  void PushBytes(const uint8_t *bytes, size_t size) { buf_.push(bytes, size); }
-
-  void PopBytes(size_t amount) { buf_.pop(amount); }
-
-  template<typename T> void AssertScalarT() {
-    // The code assumes power of 2 sizes and endian-swap-ability.
-    static_assert(flatbuffers::is_scalar<T>::value, "T must be a scalar type");
-  }
-
-  // Write a single aligned scalar to the buffer
-  template<typename T> uoffset_t PushElement(T element) {
-    AssertScalarT<T>();
-    Align(sizeof(T));
-    buf_.push_small(EndianScalar(element));
-    return GetSize();
-  }
-
-  template<typename T> uoffset_t PushElement(Offset<T> off) {
-    // Special case for offsets: see ReferTo below.
-    return PushElement(ReferTo(off.o));
-  }
-
-  // When writing fields, we track where they are, so we can create correct
-  // vtables later.
-  void TrackField(voffset_t field, uoffset_t off) {
-    FieldLoc fl = { off, field };
-    buf_.scratch_push_small(fl);
-    num_field_loc++;
-    max_voffset_ = (std::max)(max_voffset_, field);
-  }
-
-  // Like PushElement, but additionally tracks the field this represents.
-  template<typename T> void AddElement(voffset_t field, T e, T def) {
-    // We don't serialize values equal to the default.
-    if (IsTheSameAs(e, def) && !force_defaults_) return;
-    auto off = PushElement(e);
-    TrackField(field, off);
-  }
-
-  template<typename T> void AddElement(voffset_t field, T e) {
-    auto off = PushElement(e);
-    TrackField(field, off);
-  }
-
-  template<typename T> void AddOffset(voffset_t field, Offset<T> off) {
-    if (off.IsNull()) return;  // Don't store.
-    AddElement(field, ReferTo(off.o), static_cast<uoffset_t>(0));
-  }
-
-  template<typename T> void AddStruct(voffset_t field, const T *structptr) {
-    if (!structptr) return;  // Default, don't store.
-    Align(AlignOf<T>());
-    buf_.push_small(*structptr);
-    TrackField(field, GetSize());
-  }
-
-  void AddStructOffset(voffset_t field, uoffset_t off) {
-    TrackField(field, off);
-  }
-
-  // Offsets initially are relative to the end of the buffer (downwards).
-  // This function converts them to be relative to the current location
-  // in the buffer (when stored here), pointing upwards.
-  uoffset_t ReferTo(uoffset_t off) {
-    // Align to ensure GetSize() below is correct.
-    Align(sizeof(uoffset_t));
-    // Offset must refer to something already in buffer.
-    FLATBUFFERS_ASSERT(off && off <= GetSize());
-    return GetSize() - off + static_cast<uoffset_t>(sizeof(uoffset_t));
-  }
-
-  void NotNested() {
-    // If you hit this, you're trying to construct a Table/Vector/String
-    // during the construction of its parent table (between the MyTableBuilder
-    // and table.Finish().
-    // Move the creation of these sub-objects to above the MyTableBuilder to
-    // not get this assert.
-    // Ignoring this assert may appear to work in simple cases, but the reason
-    // it is here is that storing objects in-line may cause vtable offsets
-    // to not fit anymore. It also leads to vtable duplication.
-    FLATBUFFERS_ASSERT(!nested);
-    // If you hit this, fields were added outside the scope of a table.
-    FLATBUFFERS_ASSERT(!num_field_loc);
-  }
-
-  // From generated code (or from the parser), we call StartTable/EndTable
-  // with a sequence of AddElement calls in between.
-  uoffset_t StartTable() {
-    NotNested();
-    nested = true;
-    return GetSize();
-  }
-
-  // This finishes one serialized object by generating the vtable if it's a
-  // table, comparing it against existing vtables, and writing the
-  // resulting vtable offset.
-  uoffset_t EndTable(uoffset_t start) {
-    // If you get this assert, a corresponding StartTable wasn't called.
-    FLATBUFFERS_ASSERT(nested);
-    // Write the vtable offset, which is the start of any Table.
-    // We fill it's value later.
-    auto vtableoffsetloc = PushElement<soffset_t>(0);
-    // Write a vtable, which consists entirely of voffset_t elements.
-    // It starts with the number of offsets, followed by a type id, followed
-    // by the offsets themselves. In reverse:
-    // Include space for the last offset and ensure empty tables have a
-    // minimum size.
-    max_voffset_ =
-        (std::max)(static_cast<voffset_t>(max_voffset_ + sizeof(voffset_t)),
-                   FieldIndexToOffset(0));
-    buf_.fill_big(max_voffset_);
-    auto table_object_size = vtableoffsetloc - start;
-    // Vtable use 16bit offsets.
-    FLATBUFFERS_ASSERT(table_object_size < 0x10000);
-    WriteScalar<voffset_t>(buf_.data() + sizeof(voffset_t),
-                           static_cast<voffset_t>(table_object_size));
-    WriteScalar<voffset_t>(buf_.data(), max_voffset_);
-    // Write the offsets into the table
-    for (auto it = buf_.scratch_end() - num_field_loc * sizeof(FieldLoc);
-         it < buf_.scratch_end(); it += sizeof(FieldLoc)) {
-      auto field_location = reinterpret_cast<FieldLoc *>(it);
-      auto pos = static_cast<voffset_t>(vtableoffsetloc - field_location->off);
-      // If this asserts, it means you've set a field twice.
-      FLATBUFFERS_ASSERT(
-          !ReadScalar<voffset_t>(buf_.data() + field_location->id));
-      WriteScalar<voffset_t>(buf_.data() + field_location->id, pos);
-    }
-    ClearOffsets();
-    auto vt1 = reinterpret_cast<voffset_t *>(buf_.data());
-    auto vt1_size = ReadScalar<voffset_t>(vt1);
-    auto vt_use = GetSize();
-    // See if we already have generated a vtable with this exact same
-    // layout before. If so, make it point to the old one, remove this one.
-    if (dedup_vtables_) {
-      for (auto it = buf_.scratch_data(); it < buf_.scratch_end();
-           it += sizeof(uoffset_t)) {
-        auto vt_offset_ptr = reinterpret_cast<uoffset_t *>(it);
-        auto vt2 = reinterpret_cast<voffset_t *>(buf_.data_at(*vt_offset_ptr));
-        auto vt2_size = ReadScalar<voffset_t>(vt2);
-        if (vt1_size != vt2_size || 0 != memcmp(vt2, vt1, vt1_size)) continue;
-        vt_use = *vt_offset_ptr;
-        buf_.pop(GetSize() - vtableoffsetloc);
-        break;
-      }
-    }
-    // If this is a new vtable, remember it.
-    if (vt_use == GetSize()) { buf_.scratch_push_small(vt_use); }
-    // Fill the vtable offset we created above.
-    // The offset points from the beginning of the object to where the
-    // vtable is stored.
-    // Offsets default direction is downward in memory for future format
-    // flexibility (storing all vtables at the start of the file).
-    WriteScalar(buf_.data_at(vtableoffsetloc),
-                static_cast<soffset_t>(vt_use) -
-                    static_cast<soffset_t>(vtableoffsetloc));
-
-    nested = false;
-    return vtableoffsetloc;
-  }
-
-  FLATBUFFERS_ATTRIBUTE(deprecated("call the version above instead"))
-  uoffset_t EndTable(uoffset_t start, voffset_t /*numfields*/) {
-    return EndTable(start);
-  }
-
-  // This checks a required field has been set in a given table that has
-  // just been constructed.
-  template<typename T> void Required(Offset<T> table, voffset_t field);
-
-  uoffset_t StartStruct(size_t alignment) {
-    Align(alignment);
-    return GetSize();
-  }
-
-  uoffset_t EndStruct() { return GetSize(); }
-
-  void ClearOffsets() {
-    buf_.scratch_pop(num_field_loc * sizeof(FieldLoc));
-    num_field_loc = 0;
-    max_voffset_ = 0;
-  }
-
-  // Aligns such that when "len" bytes are written, an object can be written
-  // after it with "alignment" without padding.
-  void PreAlign(size_t len, size_t alignment) {
-    TrackMinAlign(alignment);
-    buf_.fill(PaddingBytes(GetSize() + len, alignment));
-  }
-  template<typename T> void PreAlign(size_t len) {
-    AssertScalarT<T>();
-    PreAlign(len, sizeof(T));
-  }
-  /// @endcond
-
-  /// @brief Store a string in the buffer, which can contain any binary data.
-  /// @param[in] str A const char pointer to the data to be stored as a string.
-  /// @param[in] len The number of bytes that should be stored from `str`.
-  /// @return Returns the offset in the buffer where the string starts.
-  Offset<String> CreateString(const char *str, size_t len) {
-    NotNested();
-    PreAlign<uoffset_t>(len + 1);  // Always 0-terminated.
-    buf_.fill(1);
-    PushBytes(reinterpret_cast<const uint8_t *>(str), len);
-    PushElement(static_cast<uoffset_t>(len));
-    return Offset<String>(GetSize());
-  }
-
-  /// @brief Store a string in the buffer, which is null-terminated.
-  /// @param[in] str A const char pointer to a C-string to add to the buffer.
-  /// @return Returns the offset in the buffer where the string starts.
-  Offset<String> CreateString(const char *str) {
-    return CreateString(str, strlen(str));
-  }
-
-  /// @brief Store a string in the buffer, which is null-terminated.
-  /// @param[in] str A char pointer to a C-string to add to the buffer.
-  /// @return Returns the offset in the buffer where the string starts.
-  Offset<String> CreateString(char *str) {
-    return CreateString(str, strlen(str));
-  }
-
-  /// @brief Store a string in the buffer, which can contain any binary data.
-  /// @param[in] str A const reference to a std::string to store in the buffer.
-  /// @return Returns the offset in the buffer where the string starts.
-  Offset<String> CreateString(const std::string &str) {
-    return CreateString(str.c_str(), str.length());
-  }
-
-  // clang-format off
-  #ifdef FLATBUFFERS_HAS_STRING_VIEW
-  /// @brief Store a string in the buffer, which can contain any binary data.
-  /// @param[in] str A const string_view to copy in to the buffer.
-  /// @return Returns the offset in the buffer where the string starts.
-  Offset<String> CreateString(flatbuffers::string_view str) {
-    return CreateString(str.data(), str.size());
-  }
-  #endif // FLATBUFFERS_HAS_STRING_VIEW
-  // clang-format on
-
-  /// @brief Store a string in the buffer, which can contain any binary data.
-  /// @param[in] str A const pointer to a `String` struct to add to the buffer.
-  /// @return Returns the offset in the buffer where the string starts
-  Offset<String> CreateString(const String *str) {
-    return str ? CreateString(str->c_str(), str->size()) : 0;
-  }
-
-  /// @brief Store a string in the buffer, which can contain any binary data.
-  /// @param[in] str A const reference to a std::string like type with support
-  /// of T::c_str() and T::length() to store in the buffer.
-  /// @return Returns the offset in the buffer where the string starts.
-  template<typename T> Offset<String> CreateString(const T &str) {
-    return CreateString(str.c_str(), str.length());
-  }
-
-  /// @brief Store a string in the buffer, which can contain any binary data.
-  /// If a string with this exact contents has already been serialized before,
-  /// instead simply returns the offset of the existing string. This uses a map
-  /// stored on the heap, but only stores the numerical offsets.
-  /// @param[in] str A const char pointer to the data to be stored as a string.
-  /// @param[in] len The number of bytes that should be stored from `str`.
-  /// @return Returns the offset in the buffer where the string starts.
-  Offset<String> CreateSharedString(const char *str, size_t len) {
-    FLATBUFFERS_ASSERT(FLATBUFFERS_GENERAL_HEAP_ALLOC_OK);
-    if (!string_pool)
-      string_pool = new StringOffsetMap(StringOffsetCompare(buf_));
-    auto size_before_string = buf_.size();
-    // Must first serialize the string, since the set is all offsets into
-    // buffer.
-    auto off = CreateString(str, len);
-    auto it = string_pool->find(off);
-    // If it exists we reuse existing serialized data!
-    if (it != string_pool->end()) {
-      // We can remove the string we serialized.
-      buf_.pop(buf_.size() - size_before_string);
-      return *it;
-    }
-    // Record this string for future use.
-    string_pool->insert(off);
-    return off;
-  }
-
-#ifdef FLATBUFFERS_HAS_STRING_VIEW
-  /// @brief Store a string in the buffer, which can contain any binary data.
-  /// If a string with this exact contents has already been serialized before,
-  /// instead simply returns the offset of the existing string. This uses a map
-  /// stored on the heap, but only stores the numerical offsets.
-  /// @param[in] str A const std::string_view to store in the buffer.
-  /// @return Returns the offset in the buffer where the string starts
-  Offset<String> CreateSharedString(const flatbuffers::string_view str) {
-    return CreateSharedString(str.data(), str.size());
-  }
-#else
-  /// @brief Store a string in the buffer, which null-terminated.
-  /// If a string with this exact contents has already been serialized before,
-  /// instead simply returns the offset of the existing string. This uses a map
-  /// stored on the heap, but only stores the numerical offsets.
-  /// @param[in] str A const char pointer to a C-string to add to the buffer.
-  /// @return Returns the offset in the buffer where the string starts.
-  Offset<String> CreateSharedString(const char *str) {
-    return CreateSharedString(str, strlen(str));
-  }
-
-  /// @brief Store a string in the buffer, which can contain any binary data.
-  /// If a string with this exact contents has already been serialized before,
-  /// instead simply returns the offset of the existing string. This uses a map
-  /// stored on the heap, but only stores the numerical offsets.
-  /// @param[in] str A const reference to a std::string to store in the buffer.
-  /// @return Returns the offset in the buffer where the string starts.
-  Offset<String> CreateSharedString(const std::string &str) {
-    return CreateSharedString(str.c_str(), str.length());
-  }
-#endif
-
-  /// @brief Store a string in the buffer, which can contain any binary data.
-  /// If a string with this exact contents has already been serialized before,
-  /// instead simply returns the offset of the existing string. This uses a map
-  /// stored on the heap, but only stores the numerical offsets.
-  /// @param[in] str A const pointer to a `String` struct to add to the buffer.
-  /// @return Returns the offset in the buffer where the string starts
-  Offset<String> CreateSharedString(const String *str) {
-    return CreateSharedString(str->c_str(), str->size());
-  }
-
-  /// @cond FLATBUFFERS_INTERNAL
-  uoffset_t EndVector(size_t len) {
-    FLATBUFFERS_ASSERT(nested);  // Hit if no corresponding StartVector.
-    nested = false;
-    return PushElement(static_cast<uoffset_t>(len));
-  }
-
-  void StartVector(size_t len, size_t elemsize) {
-    NotNested();
-    nested = true;
-    PreAlign<uoffset_t>(len * elemsize);
-    PreAlign(len * elemsize, elemsize);  // Just in case elemsize > uoffset_t.
-  }
-
-  // Call this right before StartVector/CreateVector if you want to force the
-  // alignment to be something different than what the element size would
-  // normally dictate.
-  // This is useful when storing a nested_flatbuffer in a vector of bytes,
-  // or when storing SIMD floats, etc.
-  void ForceVectorAlignment(size_t len, size_t elemsize, size_t alignment) {
-    FLATBUFFERS_ASSERT(VerifyAlignmentRequirements(alignment));
-    PreAlign(len * elemsize, alignment);
-  }
-
-  // Similar to ForceVectorAlignment but for String fields.
-  void ForceStringAlignment(size_t len, size_t alignment) {
-    FLATBUFFERS_ASSERT(VerifyAlignmentRequirements(alignment));
-    PreAlign((len + 1) * sizeof(char), alignment);
-  }
-
-  /// @endcond
-
-  /// @brief Serialize an array into a FlatBuffer `vector`.
-  /// @tparam T The data type of the array elements.
-  /// @param[in] v A pointer to the array of type `T` to serialize into the
-  /// buffer as a `vector`.
-  /// @param[in] len The number of elements to serialize.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  template<typename T> Offset<Vector<T>> CreateVector(const T *v, size_t len) {
-    // If this assert hits, you're specifying a template argument that is
-    // causing the wrong overload to be selected, remove it.
-    AssertScalarT<T>();
-    StartVector(len, sizeof(T));
-    if (len == 0) { return Offset<Vector<T>>(EndVector(len)); }
-    // clang-format off
-    #if FLATBUFFERS_LITTLEENDIAN
-      PushBytes(reinterpret_cast<const uint8_t *>(v), len * sizeof(T));
-    #else
-      if (sizeof(T) == 1) {
-        PushBytes(reinterpret_cast<const uint8_t *>(v), len);
-      } else {
-        for (auto i = len; i > 0; ) {
-          PushElement(v[--i]);
-        }
-      }
-    #endif
-    // clang-format on
-    return Offset<Vector<T>>(EndVector(len));
-  }
-
-  template<typename T>
-  Offset<Vector<Offset<T>>> CreateVector(const Offset<T> *v, size_t len) {
-    StartVector(len, sizeof(Offset<T>));
-    for (auto i = len; i > 0;) { PushElement(v[--i]); }
-    return Offset<Vector<Offset<T>>>(EndVector(len));
-  }
-
-  /// @brief Serialize a `std::vector` into a FlatBuffer `vector`.
-  /// @tparam T The data type of the `std::vector` elements.
-  /// @param v A const reference to the `std::vector` to serialize into the
-  /// buffer as a `vector`.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  template<typename T, typename Alloc>
-  Offset<Vector<T>> CreateVector(const std::vector<T, Alloc> &v) {
-    return CreateVector(data(v), v.size());
-  }
-
-  // vector<bool> may be implemented using a bit-set, so we can't access it as
-  // an array. Instead, read elements manually.
-  // Background: https://isocpp.org/blog/2012/11/on-vectorbool
-  Offset<Vector<uint8_t>> CreateVector(const std::vector<bool> &v) {
-    StartVector(v.size(), sizeof(uint8_t));
-    for (auto i = v.size(); i > 0;) {
-      PushElement(static_cast<uint8_t>(v[--i]));
-    }
-    return Offset<Vector<uint8_t>>(EndVector(v.size()));
-  }
-
-  // clang-format off
-  #ifndef FLATBUFFERS_CPP98_STL
-  /// @brief Serialize values returned by a function into a FlatBuffer `vector`.
-  /// This is a convenience function that takes care of iteration for you.
-  /// @tparam T The data type of the `std::vector` elements.
-  /// @param f A function that takes the current iteration 0..vector_size-1 and
-  /// returns any type that you can construct a FlatBuffers vector out of.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  template<typename T> Offset<Vector<T>> CreateVector(size_t vector_size,
-      const std::function<T (size_t i)> &f) {
-    FLATBUFFERS_ASSERT(FLATBUFFERS_GENERAL_HEAP_ALLOC_OK);
-    std::vector<T> elems(vector_size);
-    for (size_t i = 0; i < vector_size; i++) elems[i] = f(i);
-    return CreateVector(elems);
-  }
-  #endif // FLATBUFFERS_CPP98_STL
-  // clang-format on
-
-  /// @brief Serialize values returned by a function into a FlatBuffer `vector`.
-  /// This is a convenience function that takes care of iteration for you. This
-  /// uses a vector stored on the heap to store the intermediate results of the
-  /// iteration.
-  /// @tparam T The data type of the `std::vector` elements.
-  /// @param f A function that takes the current iteration 0..vector_size-1,
-  /// and the state parameter returning any type that you can construct a
-  /// FlatBuffers vector out of.
-  /// @param state State passed to f.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  template<typename T, typename F, typename S>
-  Offset<Vector<T>> CreateVector(size_t vector_size, F f, S *state) {
-    FLATBUFFERS_ASSERT(FLATBUFFERS_GENERAL_HEAP_ALLOC_OK);
-    std::vector<T> elems(vector_size);
-    for (size_t i = 0; i < vector_size; i++) elems[i] = f(i, state);
-    return CreateVector(elems);
-  }
-
-  /// @brief Serialize a `std::vector<std::string>` into a FlatBuffer `vector`.
-  /// This is a convenience function for a common case.
-  /// @param v A const reference to the `std::vector` to serialize into the
-  /// buffer as a `vector`.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  template<typename Alloc>
-  Offset<Vector<Offset<String>>> CreateVectorOfStrings(
-      const std::vector<std::string, Alloc> &v) {
-    return CreateVectorOfStrings(v.cbegin(), v.cend());
-  }
-
-  /// @brief Serialize a collection of Strings into a FlatBuffer `vector`.
-  /// This is a convenience function for a common case.
-  /// @param begin The begining iterator of the collection
-  /// @param end The ending iterator of the collection
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  template<class It>
-  Offset<Vector<Offset<String>>> CreateVectorOfStrings(It begin, It end) {
-    auto size = std::distance(begin, end);
-    auto scratch_buffer_usage = size * sizeof(Offset<String>);
-    // If there is not enough space to store the offsets, there definitely won't
-    // be enough space to store all the strings. So ensuring space for the
-    // scratch region is OK, for it it fails, it would have failed later.
-    buf_.ensure_space(scratch_buffer_usage);
-    for (auto it = begin; it != end; ++it) {
-      buf_.scratch_push_small(CreateString(*it));
-    }
-    StartVector(size, sizeof(Offset<String>));
-    for (auto i = 1; i <= size; i++) {
-      // Note we re-evaluate the buf location each iteration to account for any
-      // underlying buffer resizing that may occur.
-      PushElement(*reinterpret_cast<Offset<String> *>(
-          buf_.scratch_end() - i * sizeof(Offset<String>)));
-    }
-    buf_.scratch_pop(scratch_buffer_usage);
-    return Offset<Vector<Offset<String>>>(EndVector(size));
-  }
-
-  /// @brief Serialize an array of structs into a FlatBuffer `vector`.
-  /// @tparam T The data type of the struct array elements.
-  /// @param[in] v A pointer to the array of type `T` to serialize into the
-  /// buffer as a `vector`.
-  /// @param[in] len The number of elements to serialize.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  template<typename T>
-  Offset<Vector<const T *>> CreateVectorOfStructs(const T *v, size_t len) {
-    StartVector(len * sizeof(T) / AlignOf<T>(), AlignOf<T>());
-    if (len > 0) {
-      PushBytes(reinterpret_cast<const uint8_t *>(v), sizeof(T) * len);
-    }
-    return Offset<Vector<const T *>>(EndVector(len));
-  }
-
-  /// @brief Serialize an array of native structs into a FlatBuffer `vector`.
-  /// @tparam T The data type of the struct array elements.
-  /// @tparam S The data type of the native struct array elements.
-  /// @param[in] v A pointer to the array of type `S` to serialize into the
-  /// buffer as a `vector`.
-  /// @param[in] len The number of elements to serialize.
-  /// @param[in] pack_func Pointer to a function to convert the native struct
-  /// to the FlatBuffer struct.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  template<typename T, typename S>
-  Offset<Vector<const T *>> CreateVectorOfNativeStructs(
-      const S *v, size_t len, T (*const pack_func)(const S &)) {
-    FLATBUFFERS_ASSERT(pack_func);
-    auto structs = StartVectorOfStructs<T>(len);
-    for (size_t i = 0; i < len; i++) { structs[i] = pack_func(v[i]); }
-    return EndVectorOfStructs<T>(len);
-  }
-
-  /// @brief Serialize an array of native structs into a FlatBuffer `vector`.
-  /// @tparam T The data type of the struct array elements.
-  /// @tparam S The data type of the native struct array elements.
-  /// @param[in] v A pointer to the array of type `S` to serialize into the
-  /// buffer as a `vector`.
-  /// @param[in] len The number of elements to serialize.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  template<typename T, typename S>
-  Offset<Vector<const T *>> CreateVectorOfNativeStructs(const S *v,
-                                                        size_t len) {
-    extern T Pack(const S &);
-    return CreateVectorOfNativeStructs(v, len, Pack);
-  }
-
-  // clang-format off
-  #ifndef FLATBUFFERS_CPP98_STL
-  /// @brief Serialize an array of structs into a FlatBuffer `vector`.
-  /// @tparam T The data type of the struct array elements.
-  /// @param[in] filler A function that takes the current iteration 0..vector_size-1
-  /// and a pointer to the struct that must be filled.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  /// This is mostly useful when flatbuffers are generated with mutation
-  /// accessors.
-  template<typename T> Offset<Vector<const T *>> CreateVectorOfStructs(
-      size_t vector_size, const std::function<void(size_t i, T *)> &filler) {
-    T* structs = StartVectorOfStructs<T>(vector_size);
-    for (size_t i = 0; i < vector_size; i++) {
-      filler(i, structs);
-      structs++;
-    }
-    return EndVectorOfStructs<T>(vector_size);
-  }
-  #endif
-  // clang-format on
-
-  /// @brief Serialize an array of structs into a FlatBuffer `vector`.
-  /// @tparam T The data type of the struct array elements.
-  /// @param[in] f A function that takes the current iteration 0..vector_size-1,
-  /// a pointer to the struct that must be filled and the state argument.
-  /// @param[in] state Arbitrary state to pass to f.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  /// This is mostly useful when flatbuffers are generated with mutation
-  /// accessors.
-  template<typename T, typename F, typename S>
-  Offset<Vector<const T *>> CreateVectorOfStructs(size_t vector_size, F f,
-                                                  S *state) {
-    T *structs = StartVectorOfStructs<T>(vector_size);
-    for (size_t i = 0; i < vector_size; i++) {
-      f(i, structs, state);
-      structs++;
-    }
-    return EndVectorOfStructs<T>(vector_size);
-  }
-
-  /// @brief Serialize a `std::vector` of structs into a FlatBuffer `vector`.
-  /// @tparam T The data type of the `std::vector` struct elements.
-  /// @param[in] v A const reference to the `std::vector` of structs to
-  /// serialize into the buffer as a `vector`.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  template<typename T, typename Alloc>
-  Offset<Vector<const T *>> CreateVectorOfStructs(
-      const std::vector<T, Alloc> &v) {
-    return CreateVectorOfStructs(data(v), v.size());
-  }
-
-  /// @brief Serialize a `std::vector` of native structs into a FlatBuffer
-  /// `vector`.
-  /// @tparam T The data type of the `std::vector` struct elements.
-  /// @tparam S The data type of the `std::vector` native struct elements.
-  /// @param[in] v A const reference to the `std::vector` of structs to
-  /// serialize into the buffer as a `vector`.
-  /// @param[in] pack_func Pointer to a function to convert the native struct
-  /// to the FlatBuffer struct.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  template<typename T, typename S, typename Alloc>
-  Offset<Vector<const T *>> CreateVectorOfNativeStructs(
-      const std::vector<S, Alloc> &v, T (*const pack_func)(const S &)) {
-    return CreateVectorOfNativeStructs<T, S>(data(v), v.size(), pack_func);
-  }
-
-  /// @brief Serialize a `std::vector` of native structs into a FlatBuffer
-  /// `vector`.
-  /// @tparam T The data type of the `std::vector` struct elements.
-  /// @tparam S The data type of the `std::vector` native struct elements.
-  /// @param[in] v A const reference to the `std::vector` of structs to
-  /// serialize into the buffer as a `vector`.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  template<typename T, typename S, typename Alloc>
-  Offset<Vector<const T *>> CreateVectorOfNativeStructs(
-      const std::vector<S, Alloc> &v) {
-    return CreateVectorOfNativeStructs<T, S>(data(v), v.size());
-  }
-
-  /// @cond FLATBUFFERS_INTERNAL
-  template<typename T> struct StructKeyComparator {
-    bool operator()(const T &a, const T &b) const {
-      return a.KeyCompareLessThan(&b);
-    }
-  };
-  /// @endcond
-
-  /// @brief Serialize a `std::vector` of structs into a FlatBuffer `vector`
-  /// in sorted order.
-  /// @tparam T The data type of the `std::vector` struct elements.
-  /// @param[in] v A const reference to the `std::vector` of structs to
-  /// serialize into the buffer as a `vector`.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  template<typename T, typename Alloc>
-  Offset<Vector<const T *>> CreateVectorOfSortedStructs(
-      std::vector<T, Alloc> *v) {
-    return CreateVectorOfSortedStructs(data(*v), v->size());
-  }
-
-  /// @brief Serialize a `std::vector` of native structs into a FlatBuffer
-  /// `vector` in sorted order.
-  /// @tparam T The data type of the `std::vector` struct elements.
-  /// @tparam S The data type of the `std::vector` native struct elements.
-  /// @param[in] v A const reference to the `std::vector` of structs to
-  /// serialize into the buffer as a `vector`.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  template<typename T, typename S, typename Alloc>
-  Offset<Vector<const T *>> CreateVectorOfSortedNativeStructs(
-      std::vector<S, Alloc> *v) {
-    return CreateVectorOfSortedNativeStructs<T, S>(data(*v), v->size());
-  }
-
-  /// @brief Serialize an array of structs into a FlatBuffer `vector` in sorted
-  /// order.
-  /// @tparam T The data type of the struct array elements.
-  /// @param[in] v A pointer to the array of type `T` to serialize into the
-  /// buffer as a `vector`.
-  /// @param[in] len The number of elements to serialize.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  template<typename T>
-  Offset<Vector<const T *>> CreateVectorOfSortedStructs(T *v, size_t len) {
-    std::sort(v, v + len, StructKeyComparator<T>());
-    return CreateVectorOfStructs(v, len);
-  }
-
-  /// @brief Serialize an array of native structs into a FlatBuffer `vector` in
-  /// sorted order.
-  /// @tparam T The data type of the struct array elements.
-  /// @tparam S The data type of the native struct array elements.
-  /// @param[in] v A pointer to the array of type `S` to serialize into the
-  /// buffer as a `vector`.
-  /// @param[in] len The number of elements to serialize.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  template<typename T, typename S>
-  Offset<Vector<const T *>> CreateVectorOfSortedNativeStructs(S *v,
-                                                              size_t len) {
-    extern T Pack(const S &);
-    auto structs = StartVectorOfStructs<T>(len);
-    for (size_t i = 0; i < len; i++) { structs[i] = Pack(v[i]); }
-    std::sort(structs, structs + len, StructKeyComparator<T>());
-    return EndVectorOfStructs<T>(len);
-  }
-
-  /// @cond FLATBUFFERS_INTERNAL
-  template<typename T> struct TableKeyComparator {
-    TableKeyComparator(vector_downward &buf) : buf_(buf) {}
-    TableKeyComparator(const TableKeyComparator &other) : buf_(other.buf_) {}
-    bool operator()(const Offset<T> &a, const Offset<T> &b) const {
-      auto table_a = reinterpret_cast<T *>(buf_.data_at(a.o));
-      auto table_b = reinterpret_cast<T *>(buf_.data_at(b.o));
-      return table_a->KeyCompareLessThan(table_b);
-    }
-    vector_downward &buf_;
-
-   private:
-    FLATBUFFERS_DELETE_FUNC(
-        TableKeyComparator &operator=(const TableKeyComparator &other));
-  };
-  /// @endcond
-
-  /// @brief Serialize an array of `table` offsets as a `vector` in the buffer
-  /// in sorted order.
-  /// @tparam T The data type that the offset refers to.
-  /// @param[in] v An array of type `Offset<T>` that contains the `table`
-  /// offsets to store in the buffer in sorted order.
-  /// @param[in] len The number of elements to store in the `vector`.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  template<typename T>
-  Offset<Vector<Offset<T>>> CreateVectorOfSortedTables(Offset<T> *v,
-                                                       size_t len) {
-    std::sort(v, v + len, TableKeyComparator<T>(buf_));
-    return CreateVector(v, len);
-  }
-
-  /// @brief Serialize an array of `table` offsets as a `vector` in the buffer
-  /// in sorted order.
-  /// @tparam T The data type that the offset refers to.
-  /// @param[in] v An array of type `Offset<T>` that contains the `table`
-  /// offsets to store in the buffer in sorted order.
-  /// @return Returns a typed `Offset` into the serialized data indicating
-  /// where the vector is stored.
-  template<typename T, typename Alloc>
-  Offset<Vector<Offset<T>>> CreateVectorOfSortedTables(
-      std::vector<Offset<T>, Alloc> *v) {
-    return CreateVectorOfSortedTables(data(*v), v->size());
-  }
-
-  /// @brief Specialized version of `CreateVector` for non-copying use cases.
-  /// Write the data any time later to the returned buffer pointer `buf`.
-  /// @param[in] len The number of elements to store in the `vector`.
-  /// @param[in] elemsize The size of each element in the `vector`.
-  /// @param[out] buf A pointer to a `uint8_t` pointer that can be
-  /// written to at a later time to serialize the data into a `vector`
-  /// in the buffer.
-  uoffset_t CreateUninitializedVector(size_t len, size_t elemsize,
-                                      uint8_t **buf) {
-    NotNested();
-    StartVector(len, elemsize);
-    buf_.make_space(len * elemsize);
-    auto vec_start = GetSize();
-    auto vec_end = EndVector(len);
-    *buf = buf_.data_at(vec_start);
-    return vec_end;
-  }
-
-  /// @brief Specialized version of `CreateVector` for non-copying use cases.
-  /// Write the data any time later to the returned buffer pointer `buf`.
-  /// @tparam T The data type of the data that will be stored in the buffer
-  /// as a `vector`.
-  /// @param[in] len The number of elements to store in the `vector`.
-  /// @param[out] buf A pointer to a pointer of type `T` that can be
-  /// written to at a later time to serialize the data into a `vector`
-  /// in the buffer.
-  template<typename T>
-  Offset<Vector<T>> CreateUninitializedVector(size_t len, T **buf) {
-    AssertScalarT<T>();
-    return CreateUninitializedVector(len, sizeof(T),
-                                     reinterpret_cast<uint8_t **>(buf));
-  }
-
-  template<typename T>
-  Offset<Vector<const T *>> CreateUninitializedVectorOfStructs(size_t len,
-                                                               T **buf) {
-    return CreateUninitializedVector(len, sizeof(T),
-                                     reinterpret_cast<uint8_t **>(buf));
-  }
-
-  // @brief Create a vector of scalar type T given as input a vector of scalar
-  // type U, useful with e.g. pre "enum class" enums, or any existing scalar
-  // data of the wrong type.
-  template<typename T, typename U>
-  Offset<Vector<T>> CreateVectorScalarCast(const U *v, size_t len) {
-    AssertScalarT<T>();
-    AssertScalarT<U>();
-    StartVector(len, sizeof(T));
-    for (auto i = len; i > 0;) { PushElement(static_cast<T>(v[--i])); }
-    return Offset<Vector<T>>(EndVector(len));
-  }
-
-  /// @brief Write a struct by itself, typically to be part of a union.
-  template<typename T> Offset<const T *> CreateStruct(const T &structobj) {
-    NotNested();
-    Align(AlignOf<T>());
-    buf_.push_small(structobj);
-    return Offset<const T *>(GetSize());
-  }
-
-  /// @brief The length of a FlatBuffer file header.
-  static const size_t kFileIdentifierLength = 4;
-
-  /// @brief Finish serializing a buffer by writing the root offset.
-  /// @param[in] file_identifier If a `file_identifier` is given, the buffer
-  /// will be prefixed with a standard FlatBuffers file header.
-  template<typename T>
-  void Finish(Offset<T> root, const char *file_identifier = nullptr) {
-    Finish(root.o, file_identifier, false);
-  }
-
-  /// @brief Finish a buffer with a 32 bit size field pre-fixed (size of the
-  /// buffer following the size field). These buffers are NOT compatible
-  /// with standard buffers created by Finish, i.e. you can't call GetRoot
-  /// on them, you have to use GetSizePrefixedRoot instead.
-  /// All >32 bit quantities in this buffer will be aligned when the whole
-  /// size pre-fixed buffer is aligned.
-  /// These kinds of buffers are useful for creating a stream of FlatBuffers.
-  template<typename T>
-  void FinishSizePrefixed(Offset<T> root,
-                          const char *file_identifier = nullptr) {
-    Finish(root.o, file_identifier, true);
-  }
-
-  void SwapBufAllocator(FlatBufferBuilder &other) {
-    buf_.swap_allocator(other.buf_);
-  }
-
- protected:
-  // You shouldn't really be copying instances of this class.
-  FlatBufferBuilder(const FlatBufferBuilder &);
-  FlatBufferBuilder &operator=(const FlatBufferBuilder &);
-
-  void Finish(uoffset_t root, const char *file_identifier, bool size_prefix) {
-    NotNested();
-    buf_.clear_scratch();
-    // This will cause the whole buffer to be aligned.
-    PreAlign((size_prefix ? sizeof(uoffset_t) : 0) + sizeof(uoffset_t) +
-                 (file_identifier ? kFileIdentifierLength : 0),
-             minalign_);
-    if (file_identifier) {
-      FLATBUFFERS_ASSERT(strlen(file_identifier) == kFileIdentifierLength);
-      PushBytes(reinterpret_cast<const uint8_t *>(file_identifier),
-                kFileIdentifierLength);
-    }
-    PushElement(ReferTo(root));  // Location of root.
-    if (size_prefix) { PushElement(GetSize()); }
-    finished = true;
-  }
-
-  struct FieldLoc {
-    uoffset_t off;
-    voffset_t id;
-  };
-
-  vector_downward buf_;
-
-  // Accumulating offsets of table members while it is being built.
-  // We store these in the scratch pad of buf_, after the vtable offsets.
-  uoffset_t num_field_loc;
-  // Track how much of the vtable is in use, so we can output the most compact
-  // possible vtable.
-  voffset_t max_voffset_;
-
-  // Ensure objects are not nested.
-  bool nested;
-
-  // Ensure the buffer is finished before it is being accessed.
-  bool finished;
-
-  size_t minalign_;
-
-  bool force_defaults_;  // Serialize values equal to their defaults anyway.
-
-  bool dedup_vtables_;
-
-  struct StringOffsetCompare {
-    StringOffsetCompare(const vector_downward &buf) : buf_(&buf) {}
-    bool operator()(const Offset<String> &a, const Offset<String> &b) const {
-      auto stra = reinterpret_cast<const String *>(buf_->data_at(a.o));
-      auto strb = reinterpret_cast<const String *>(buf_->data_at(b.o));
-      return StringLessThan(stra->data(), stra->size(), strb->data(),
-                            strb->size());
-    }
-    const vector_downward *buf_;
-  };
-
-  // For use with CreateSharedString. Instantiated on first use only.
-  typedef std::set<Offset<String>, StringOffsetCompare> StringOffsetMap;
-  StringOffsetMap *string_pool;
-
- private:
-  // Allocates space for a vector of structures.
-  // Must be completed with EndVectorOfStructs().
-  template<typename T> T *StartVectorOfStructs(size_t vector_size) {
-    StartVector(vector_size * sizeof(T) / AlignOf<T>(), AlignOf<T>());
-    return reinterpret_cast<T *>(buf_.make_space(vector_size * sizeof(T)));
-  }
-
-  // End the vector of structures in the flatbuffers.
-  // Vector should have previously be started with StartVectorOfStructs().
-  template<typename T>
-  Offset<Vector<const T *>> EndVectorOfStructs(size_t vector_size) {
-    return Offset<Vector<const T *>>(EndVector(vector_size));
-  }
-};
-/// @}
-
-/// @cond FLATBUFFERS_INTERNAL
-// Helpers to get a typed pointer to the root object contained in the buffer.
-template<typename T> T *GetMutableRoot(void *buf) {
-  EndianCheck();
-  return reinterpret_cast<T *>(
-      reinterpret_cast<uint8_t *>(buf) +
-      EndianScalar(*reinterpret_cast<uoffset_t *>(buf)));
-}
-
-template<typename T> T *GetMutableSizePrefixedRoot(void *buf) {
-  return GetMutableRoot<T>(reinterpret_cast<uint8_t *>(buf) +
-                           sizeof(uoffset_t));
-}
-
-template<typename T> const T *GetRoot(const void *buf) {
-  return GetMutableRoot<T>(const_cast<void *>(buf));
-}
-
-template<typename T> const T *GetSizePrefixedRoot(const void *buf) {
-  return GetRoot<T>(reinterpret_cast<const uint8_t *>(buf) + sizeof(uoffset_t));
-}
-
-/// Helpers to get a typed pointer to objects that are currently being built.
-/// @warning Creating new objects will lead to reallocations and invalidates
-/// the pointer!
-template<typename T>
-T *GetMutableTemporaryPointer(FlatBufferBuilder &fbb, Offset<T> offset) {
-  return reinterpret_cast<T *>(fbb.GetCurrentBufferPointer() + fbb.GetSize() -
-                               offset.o);
-}
-
-template<typename T>
-const T *GetTemporaryPointer(FlatBufferBuilder &fbb, Offset<T> offset) {
-  return GetMutableTemporaryPointer<T>(fbb, offset);
-}
-
-/// @brief Get a pointer to the the file_identifier section of the buffer.
-/// @return Returns a const char pointer to the start of the file_identifier
-/// characters in the buffer.  The returned char * has length
-/// 'flatbuffers::FlatBufferBuilder::kFileIdentifierLength'.
-/// This function is UNDEFINED for FlatBuffers whose schema does not include
-/// a file_identifier (likely points at padding or the start of a the root
-/// vtable).
-inline const char *GetBufferIdentifier(const void *buf,
-                                       bool size_prefixed = false) {
-  return reinterpret_cast<const char *>(buf) +
-         ((size_prefixed) ? 2 * sizeof(uoffset_t) : sizeof(uoffset_t));
-}
-
-// Helper to see if the identifier in a buffer has the expected value.
-inline bool BufferHasIdentifier(const void *buf, const char *identifier,
-                                bool size_prefixed = false) {
-  return strncmp(GetBufferIdentifier(buf, size_prefixed), identifier,
-                 FlatBufferBuilder::kFileIdentifierLength) == 0;
-}
-
-// Helper class to verify the integrity of a FlatBuffer
-class Verifier FLATBUFFERS_FINAL_CLASS {
- public:
-  Verifier(const uint8_t *buf, size_t buf_len, uoffset_t _max_depth = 64,
-           uoffset_t _max_tables = 1000000, bool _check_alignment = true)
-      : buf_(buf),
-        size_(buf_len),
-        depth_(0),
-        max_depth_(_max_depth),
-        num_tables_(0),
-        max_tables_(_max_tables),
-        upper_bound_(0),
-        check_alignment_(_check_alignment) {
-    FLATBUFFERS_ASSERT(size_ < FLATBUFFERS_MAX_BUFFER_SIZE);
-  }
-
-  // Central location where any verification failures register.
-  bool Check(bool ok) const {
-    // clang-format off
-    #ifdef FLATBUFFERS_DEBUG_VERIFICATION_FAILURE
-      FLATBUFFERS_ASSERT(ok);
-    #endif
-    #ifdef FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE
-      if (!ok)
-        upper_bound_ = 0;
-    #endif
-    // clang-format on
-    return ok;
-  }
-
-  // Verify any range within the buffer.
-  bool Verify(size_t elem, size_t elem_len) const {
-    // clang-format off
-    #ifdef FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE
-      auto upper_bound = elem + elem_len;
-      if (upper_bound_ < upper_bound)
-        upper_bound_ =  upper_bound;
-    #endif
-    // clang-format on
-    return Check(elem_len < size_ && elem <= size_ - elem_len);
-  }
-
-  template<typename T> bool VerifyAlignment(size_t elem) const {
-    return Check((elem & (sizeof(T) - 1)) == 0 || !check_alignment_);
-  }
-
-  // Verify a range indicated by sizeof(T).
-  template<typename T> bool Verify(size_t elem) const {
-    return VerifyAlignment<T>(elem) && Verify(elem, sizeof(T));
-  }
-
-  bool VerifyFromPointer(const uint8_t *p, size_t len) {
-    auto o = static_cast<size_t>(p - buf_);
-    return Verify(o, len);
-  }
-
-  // Verify relative to a known-good base pointer.
-  bool Verify(const uint8_t *base, voffset_t elem_off, size_t elem_len) const {
-    return Verify(static_cast<size_t>(base - buf_) + elem_off, elem_len);
-  }
-
-  template<typename T>
-  bool Verify(const uint8_t *base, voffset_t elem_off) const {
-    return Verify(static_cast<size_t>(base - buf_) + elem_off, sizeof(T));
-  }
-
-  // Verify a pointer (may be NULL) of a table type.
-  template<typename T> bool VerifyTable(const T *table) {
-    return !table || table->Verify(*this);
-  }
-
-  // Verify a pointer (may be NULL) of any vector type.
-  template<typename T> bool VerifyVector(const Vector<T> *vec) const {
-    return !vec || VerifyVectorOrString(reinterpret_cast<const uint8_t *>(vec),
-                                        sizeof(T));
-  }
-
-  // Verify a pointer (may be NULL) of a vector to struct.
-  template<typename T> bool VerifyVector(const Vector<const T *> *vec) const {
-    return VerifyVector(reinterpret_cast<const Vector<T> *>(vec));
-  }
-
-  // Verify a pointer (may be NULL) to string.
-  bool VerifyString(const String *str) const {
-    size_t end;
-    return !str || (VerifyVectorOrString(reinterpret_cast<const uint8_t *>(str),
-                                         1, &end) &&
-                    Verify(end, 1) &&           // Must have terminator
-                    Check(buf_[end] == '\0'));  // Terminating byte must be 0.
-  }
-
-  // Common code between vectors and strings.
-  bool VerifyVectorOrString(const uint8_t *vec, size_t elem_size,
-                            size_t *end = nullptr) const {
-    auto veco = static_cast<size_t>(vec - buf_);
-    // Check we can read the size field.
-    if (!Verify<uoffset_t>(veco)) return false;
-    // Check the whole array. If this is a string, the byte past the array
-    // must be 0.
-    auto size = ReadScalar<uoffset_t>(vec);
-    auto max_elems = FLATBUFFERS_MAX_BUFFER_SIZE / elem_size;
-    if (!Check(size < max_elems))
-      return false;  // Protect against byte_size overflowing.
-    auto byte_size = sizeof(size) + elem_size * size;
-    if (end) *end = veco + byte_size;
-    return Verify(veco, byte_size);
-  }
-
-  // Special case for string contents, after the above has been called.
-  bool VerifyVectorOfStrings(const Vector<Offset<String>> *vec) const {
-    if (vec) {
-      for (uoffset_t i = 0; i < vec->size(); i++) {
-        if (!VerifyString(vec->Get(i))) return false;
-      }
-    }
-    return true;
-  }
-
-  // Special case for table contents, after the above has been called.
-  template<typename T> bool VerifyVectorOfTables(const Vector<Offset<T>> *vec) {
-    if (vec) {
-      for (uoffset_t i = 0; i < vec->size(); i++) {
-        if (!vec->Get(i)->Verify(*this)) return false;
-      }
-    }
-    return true;
-  }
-
-  __supress_ubsan__("unsigned-integer-overflow") bool VerifyTableStart(
-      const uint8_t *table) {
-    // Check the vtable offset.
-    auto tableo = static_cast<size_t>(table - buf_);
-    if (!Verify<soffset_t>(tableo)) return false;
-    // This offset may be signed, but doing the subtraction unsigned always
-    // gives the result we want.
-    auto vtableo = tableo - static_cast<size_t>(ReadScalar<soffset_t>(table));
-    // Check the vtable size field, then check vtable fits in its entirety.
-    return VerifyComplexity() && Verify<voffset_t>(vtableo) &&
-           VerifyAlignment<voffset_t>(ReadScalar<voffset_t>(buf_ + vtableo)) &&
-           Verify(vtableo, ReadScalar<voffset_t>(buf_ + vtableo));
-  }
-
-  template<typename T>
-  bool VerifyBufferFromStart(const char *identifier, size_t start) {
-    if (identifier && !Check((size_ >= 2 * sizeof(flatbuffers::uoffset_t) &&
-                              BufferHasIdentifier(buf_ + start, identifier)))) {
-      return false;
-    }
-
-    // Call T::Verify, which must be in the generated code for this type.
-    auto o = VerifyOffset(start);
-    return o && reinterpret_cast<const T *>(buf_ + start + o)->Verify(*this)
-    // clang-format off
-    #ifdef FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE
-           && GetComputedSize()
-    #endif
-        ;
-    // clang-format on
-  }
-
-  // Verify this whole buffer, starting with root type T.
-  template<typename T> bool VerifyBuffer() { return VerifyBuffer<T>(nullptr); }
-
-  template<typename T> bool VerifyBuffer(const char *identifier) {
-    return VerifyBufferFromStart<T>(identifier, 0);
-  }
-
-  template<typename T> bool VerifySizePrefixedBuffer(const char *identifier) {
-    return Verify<uoffset_t>(0U) &&
-           ReadScalar<uoffset_t>(buf_) == size_ - sizeof(uoffset_t) &&
-           VerifyBufferFromStart<T>(identifier, sizeof(uoffset_t));
-  }
-
-  uoffset_t VerifyOffset(size_t start) const {
-    if (!Verify<uoffset_t>(start)) return 0;
-    auto o = ReadScalar<uoffset_t>(buf_ + start);
-    // May not point to itself.
-    if (!Check(o != 0)) return 0;
-    // Can't wrap around / buffers are max 2GB.
-    if (!Check(static_cast<soffset_t>(o) >= 0)) return 0;
-    // Must be inside the buffer to create a pointer from it (pointer outside
-    // buffer is UB).
-    if (!Verify(start + o, 1)) return 0;
-    return o;
-  }
-
-  uoffset_t VerifyOffset(const uint8_t *base, voffset_t start) const {
-    return VerifyOffset(static_cast<size_t>(base - buf_) + start);
-  }
-
-  // Called at the start of a table to increase counters measuring data
-  // structure depth and amount, and possibly bails out with false if
-  // limits set by the constructor have been hit. Needs to be balanced
-  // with EndTable().
-  bool VerifyComplexity() {
-    depth_++;
-    num_tables_++;
-    return Check(depth_ <= max_depth_ && num_tables_ <= max_tables_);
-  }
-
-  // Called at the end of a table to pop the depth count.
-  bool EndTable() {
-    depth_--;
-    return true;
-  }
-
-  // Returns the message size in bytes
-  size_t GetComputedSize() const {
-    // clang-format off
-    #ifdef FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE
-      uintptr_t size = upper_bound_;
-      // Align the size to uoffset_t
-      size = (size - 1 + sizeof(uoffset_t)) & ~(sizeof(uoffset_t) - 1);
-      return (size > size_) ?  0 : size;
-    #else
-      // Must turn on FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE for this to work.
-      (void)upper_bound_;
-      FLATBUFFERS_ASSERT(false);
-      return 0;
-    #endif
-    // clang-format on
-  }
-
- private:
-  const uint8_t *buf_;
-  size_t size_;
-  uoffset_t depth_;
-  uoffset_t max_depth_;
-  uoffset_t num_tables_;
-  uoffset_t max_tables_;
-  mutable size_t upper_bound_;
-  bool check_alignment_;
-};
-
-// Convenient way to bundle a buffer and its length, to pass it around
-// typed by its root.
-// A BufferRef does not own its buffer.
-struct BufferRefBase {};  // for std::is_base_of
-template<typename T> struct BufferRef : BufferRefBase {
-  BufferRef() : buf(nullptr), len(0), must_free(false) {}
-  BufferRef(uint8_t *_buf, uoffset_t _len)
-      : buf(_buf), len(_len), must_free(false) {}
-
-  ~BufferRef() {
-    if (must_free) free(buf);
-  }
-
-  const T *GetRoot() const { return flatbuffers::GetRoot<T>(buf); }
-
-  bool Verify() {
-    Verifier verifier(buf, len);
-    return verifier.VerifyBuffer<T>(nullptr);
-  }
-
-  uint8_t *buf;
-  uoffset_t len;
-  bool must_free;
-};
-
-// "structs" are flat structures that do not have an offset table, thus
-// always have all members present and do not support forwards/backwards
-// compatible extensions.
-
-class Struct FLATBUFFERS_FINAL_CLASS {
- public:
-  template<typename T> T GetField(uoffset_t o) const {
-    return ReadScalar<T>(&data_[o]);
-  }
-
-  template<typename T> T GetStruct(uoffset_t o) const {
-    return reinterpret_cast<T>(&data_[o]);
-  }
-
-  const uint8_t *GetAddressOf(uoffset_t o) const { return &data_[o]; }
-  uint8_t *GetAddressOf(uoffset_t o) { return &data_[o]; }
-
- private:
-  // private constructor & copy constructor: you obtain instances of this
-  // class by pointing to existing data only
-  Struct();
-  Struct(const Struct &);
-  Struct &operator=(const Struct &);
-
-  uint8_t data_[1];
-};
-
-// "tables" use an offset table (possibly shared) that allows fields to be
-// omitted and added at will, but uses an extra indirection to read.
-class Table {
- public:
-  const uint8_t *GetVTable() const {
-    return data_ - ReadScalar<soffset_t>(data_);
-  }
-
-  // This gets the field offset for any of the functions below it, or 0
-  // if the field was not present.
-  voffset_t GetOptionalFieldOffset(voffset_t field) const {
-    // The vtable offset is always at the start.
-    auto vtable = GetVTable();
-    // The first element is the size of the vtable (fields + type id + itself).
-    auto vtsize = ReadScalar<voffset_t>(vtable);
-    // If the field we're accessing is outside the vtable, we're reading older
-    // data, so it's the same as if the offset was 0 (not present).
-    return field < vtsize ? ReadScalar<voffset_t>(vtable + field) : 0;
-  }
-
-  template<typename T> T GetField(voffset_t field, T defaultval) const {
-    auto field_offset = GetOptionalFieldOffset(field);
-    return field_offset ? ReadScalar<T>(data_ + field_offset) : defaultval;
-  }
-
-  template<typename P> P GetPointer(voffset_t field) {
-    auto field_offset = GetOptionalFieldOffset(field);
-    auto p = data_ + field_offset;
-    return field_offset ? reinterpret_cast<P>(p + ReadScalar<uoffset_t>(p))
-                        : nullptr;
-  }
-  template<typename P> P GetPointer(voffset_t field) const {
-    return const_cast<Table *>(this)->GetPointer<P>(field);
-  }
-
-  template<typename P> P GetStruct(voffset_t field) const {
-    auto field_offset = GetOptionalFieldOffset(field);
-    auto p = const_cast<uint8_t *>(data_ + field_offset);
-    return field_offset ? reinterpret_cast<P>(p) : nullptr;
-  }
-
-  template<typename Raw, typename Face>
-  flatbuffers::Optional<Face> GetOptional(voffset_t field) const {
-    auto field_offset = GetOptionalFieldOffset(field);
-    auto p = data_ + field_offset;
-    return field_offset ? Optional<Face>(static_cast<Face>(ReadScalar<Raw>(p)))
-                        : Optional<Face>();
-  }
-
-  template<typename T> bool SetField(voffset_t field, T val, T def) {
-    auto field_offset = GetOptionalFieldOffset(field);
-    if (!field_offset) return IsTheSameAs(val, def);
-    WriteScalar(data_ + field_offset, val);
-    return true;
-  }
-  template<typename T> bool SetField(voffset_t field, T val) {
-    auto field_offset = GetOptionalFieldOffset(field);
-    if (!field_offset) return false;
-    WriteScalar(data_ + field_offset, val);
-    return true;
-  }
-
-  bool SetPointer(voffset_t field, const uint8_t *val) {
-    auto field_offset = GetOptionalFieldOffset(field);
-    if (!field_offset) return false;
-    WriteScalar(data_ + field_offset,
-                static_cast<uoffset_t>(val - (data_ + field_offset)));
-    return true;
-  }
-
-  uint8_t *GetAddressOf(voffset_t field) {
-    auto field_offset = GetOptionalFieldOffset(field);
-    return field_offset ? data_ + field_offset : nullptr;
-  }
-  const uint8_t *GetAddressOf(voffset_t field) const {
-    return const_cast<Table *>(this)->GetAddressOf(field);
-  }
-
-  bool CheckField(voffset_t field) const {
-    return GetOptionalFieldOffset(field) != 0;
-  }
-
-  // Verify the vtable of this table.
-  // Call this once per table, followed by VerifyField once per field.
-  bool VerifyTableStart(Verifier &verifier) const {
-    return verifier.VerifyTableStart(data_);
-  }
-
-  // Verify a particular field.
-  template<typename T>
-  bool VerifyField(const Verifier &verifier, voffset_t field) const {
-    // Calling GetOptionalFieldOffset should be safe now thanks to
-    // VerifyTable().
-    auto field_offset = GetOptionalFieldOffset(field);
-    // Check the actual field.
-    return !field_offset || verifier.Verify<T>(data_, field_offset);
-  }
-
-  // VerifyField for required fields.
-  template<typename T>
-  bool VerifyFieldRequired(const Verifier &verifier, voffset_t field) const {
-    auto field_offset = GetOptionalFieldOffset(field);
-    return verifier.Check(field_offset != 0) &&
-           verifier.Verify<T>(data_, field_offset);
-  }
-
-  // Versions for offsets.
-  bool VerifyOffset(const Verifier &verifier, voffset_t field) const {
-    auto field_offset = GetOptionalFieldOffset(field);
-    return !field_offset || verifier.VerifyOffset(data_, field_offset);
-  }
-
-  bool VerifyOffsetRequired(const Verifier &verifier, voffset_t field) const {
-    auto field_offset = GetOptionalFieldOffset(field);
-    return verifier.Check(field_offset != 0) &&
-           verifier.VerifyOffset(data_, field_offset);
-  }
-
- private:
-  // private constructor & copy constructor: you obtain instances of this
-  // class by pointing to existing data only
-  Table();
-  Table(const Table &other);
-  Table &operator=(const Table &);
-
-  uint8_t data_[1];
-};
-
-// This specialization allows avoiding warnings like:
-// MSVC C4800: type: forcing value to bool 'true' or 'false'.
-template<>
-inline flatbuffers::Optional<bool> Table::GetOptional<uint8_t, bool>(
-    voffset_t field) const {
-  auto field_offset = GetOptionalFieldOffset(field);
-  auto p = data_ + field_offset;
-  return field_offset ? Optional<bool>(ReadScalar<uint8_t>(p) != 0)
-                      : Optional<bool>();
-}
-
-template<typename T>
-void FlatBufferBuilder::Required(Offset<T> table, voffset_t field) {
-  auto table_ptr = reinterpret_cast<const Table *>(buf_.data_at(table.o));
-  bool ok = table_ptr->GetOptionalFieldOffset(field) != 0;
-  // If this fails, the caller will show what field needs to be set.
-  FLATBUFFERS_ASSERT(ok);
-  (void)ok;
-}
 
 /// @brief This can compute the start of a FlatBuffer from a root pointer, i.e.
 /// it is the opposite transformation of GetRoot().
@@ -2836,7 +56,7 @@ inline const uint8_t *GetBufferStartFromRootPointer(const void *root) {
   // file_identifier, and alignment padding) to see which points to the root.
   // None of the other values can "impersonate" the root since they will either
   // be 0 or four ASCII characters.
-  static_assert(FlatBufferBuilder::kFileIdentifierLength == sizeof(uoffset_t),
+  static_assert(flatbuffers::kFileIdentifierLength == sizeof(uoffset_t),
                 "file_identifier is assumed to be the same size as uoffset_t");
   for (auto possible_roots = FLATBUFFERS_MAX_ALIGNMENT / sizeof(uoffset_t) + 1;
        possible_roots; possible_roots--) {
diff --git a/include/flatbuffers/registry.h b/include/flatbuffers/registry.h
index 9ea425b3..563d6206 100644
--- a/include/flatbuffers/registry.h
+++ b/include/flatbuffers/registry.h
@@ -17,6 +17,7 @@
 #ifndef FLATBUFFERS_REGISTRY_H_
 #define FLATBUFFERS_REGISTRY_H_
 
+#include "flatbuffers/base.h"
 #include "flatbuffers/idl.h"
 
 namespace flatbuffers {
@@ -40,13 +41,13 @@ class Registry {
   bool FlatBufferToText(const uint8_t *flatbuf, size_t len, std::string *dest) {
     // Get the identifier out of the buffer.
     // If the buffer is truncated, exit.
-    if (len < sizeof(uoffset_t) + FlatBufferBuilder::kFileIdentifierLength) {
+    if (len < sizeof(uoffset_t) + kFileIdentifierLength) {
       lasterror_ = "buffer truncated";
       return false;
     }
     std::string ident(
         reinterpret_cast<const char *>(flatbuf) + sizeof(uoffset_t),
-        FlatBufferBuilder::kFileIdentifierLength);
+        kFileIdentifierLength);
     // Load and parse the schema.
     Parser parser;
     if (!LoadSchema(ident, &parser)) return false;
diff --git a/include/flatbuffers/string.h b/include/flatbuffers/string.h
new file mode 100644
index 00000000..3db95fce
--- /dev/null
+++ b/include/flatbuffers/string.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2021 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FLATBUFFERS_STRING_H_
+#define FLATBUFFERS_STRING_H_
+
+#include "flatbuffers/base.h"
+#include "flatbuffers/vector.h"
+
+namespace flatbuffers {
+
+struct String : public Vector<char> {
+  const char *c_str() const { return reinterpret_cast<const char *>(Data()); }
+  std::string str() const { return std::string(c_str(), size()); }
+
+  // clang-format off
+  #ifdef FLATBUFFERS_HAS_STRING_VIEW
+  flatbuffers::string_view string_view() const {
+    return flatbuffers::string_view(c_str(), size());
+  }
+  #endif // FLATBUFFERS_HAS_STRING_VIEW
+  // clang-format on
+
+  bool operator<(const String &o) const {
+    return StringLessThan(this->data(), this->size(), o.data(), o.size());
+  }
+};
+
+// Convenience function to get std::string from a String returning an empty
+// string on null pointer.
+static inline std::string GetString(const String *str) {
+  return str ? str->str() : "";
+}
+
+// Convenience function to get char* from a String returning an empty string on
+// null pointer.
+static inline const char *GetCstring(const String *str) {
+  return str ? str->c_str() : "";
+}
+
+#ifdef FLATBUFFERS_HAS_STRING_VIEW
+// Convenience function to get string_view from a String returning an empty
+// string_view on null pointer.
+static inline flatbuffers::string_view GetStringView(const String *str) {
+  return str ? str->string_view() : flatbuffers::string_view();
+}
+#endif  // FLATBUFFERS_HAS_STRING_VIEW
+
+}  // namespace flatbuffers
+
+#endif  // FLATBUFFERS_STRING_H_
\ No newline at end of file
diff --git a/include/flatbuffers/struct.h b/include/flatbuffers/struct.h
new file mode 100644
index 00000000..d8753c84
--- /dev/null
+++ b/include/flatbuffers/struct.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2021 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FLATBUFFERS_STRUCT_H_
+#define FLATBUFFERS_STRUCT_H_
+
+#include "flatbuffers/base.h"
+
+namespace flatbuffers {
+
+// "structs" are flat structures that do not have an offset table, thus
+// always have all members present and do not support forwards/backwards
+// compatible extensions.
+
+class Struct FLATBUFFERS_FINAL_CLASS {
+ public:
+  template<typename T> T GetField(uoffset_t o) const {
+    return ReadScalar<T>(&data_[o]);
+  }
+
+  template<typename T> T GetStruct(uoffset_t o) const {
+    return reinterpret_cast<T>(&data_[o]);
+  }
+
+  const uint8_t *GetAddressOf(uoffset_t o) const { return &data_[o]; }
+  uint8_t *GetAddressOf(uoffset_t o) { return &data_[o]; }
+
+ private:
+  // private constructor & copy constructor: you obtain instances of this
+  // class by pointing to existing data only
+  Struct();
+  Struct(const Struct &);
+  Struct &operator=(const Struct &);
+
+  uint8_t data_[1];
+};
+
+}  // namespace flatbuffers
+
+#endif  // FLATBUFFERS_STRUCT_H_
\ No newline at end of file
diff --git a/include/flatbuffers/table.h b/include/flatbuffers/table.h
new file mode 100644
index 00000000..42470693
--- /dev/null
+++ b/include/flatbuffers/table.h
@@ -0,0 +1,166 @@
+/*
+ * Copyright 2021 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FLATBUFFERS_TABLE_H_
+#define FLATBUFFERS_TABLE_H_
+
+#include "flatbuffers/base.h"
+#include "flatbuffers/verifier.h"
+
+namespace flatbuffers {
+
+// "tables" use an offset table (possibly shared) that allows fields to be
+// omitted and added at will, but uses an extra indirection to read.
+class Table {
+ public:
+  const uint8_t *GetVTable() const {
+    return data_ - ReadScalar<soffset_t>(data_);
+  }
+
+  // This gets the field offset for any of the functions below it, or 0
+  // if the field was not present.
+  voffset_t GetOptionalFieldOffset(voffset_t field) const {
+    // The vtable offset is always at the start.
+    auto vtable = GetVTable();
+    // The first element is the size of the vtable (fields + type id + itself).
+    auto vtsize = ReadScalar<voffset_t>(vtable);
+    // If the field we're accessing is outside the vtable, we're reading older
+    // data, so it's the same as if the offset was 0 (not present).
+    return field < vtsize ? ReadScalar<voffset_t>(vtable + field) : 0;
+  }
+
+  template<typename T> T GetField(voffset_t field, T defaultval) const {
+    auto field_offset = GetOptionalFieldOffset(field);
+    return field_offset ? ReadScalar<T>(data_ + field_offset) : defaultval;
+  }
+
+  template<typename P> P GetPointer(voffset_t field) {
+    auto field_offset = GetOptionalFieldOffset(field);
+    auto p = data_ + field_offset;
+    return field_offset ? reinterpret_cast<P>(p + ReadScalar<uoffset_t>(p))
+                        : nullptr;
+  }
+  template<typename P> P GetPointer(voffset_t field) const {
+    return const_cast<Table *>(this)->GetPointer<P>(field);
+  }
+
+  template<typename P> P GetStruct(voffset_t field) const {
+    auto field_offset = GetOptionalFieldOffset(field);
+    auto p = const_cast<uint8_t *>(data_ + field_offset);
+    return field_offset ? reinterpret_cast<P>(p) : nullptr;
+  }
+
+  template<typename Raw, typename Face>
+  flatbuffers::Optional<Face> GetOptional(voffset_t field) const {
+    auto field_offset = GetOptionalFieldOffset(field);
+    auto p = data_ + field_offset;
+    return field_offset ? Optional<Face>(static_cast<Face>(ReadScalar<Raw>(p)))
+                        : Optional<Face>();
+  }
+
+  template<typename T> bool SetField(voffset_t field, T val, T def) {
+    auto field_offset = GetOptionalFieldOffset(field);
+    if (!field_offset) return IsTheSameAs(val, def);
+    WriteScalar(data_ + field_offset, val);
+    return true;
+  }
+  template<typename T> bool SetField(voffset_t field, T val) {
+    auto field_offset = GetOptionalFieldOffset(field);
+    if (!field_offset) return false;
+    WriteScalar(data_ + field_offset, val);
+    return true;
+  }
+
+  bool SetPointer(voffset_t field, const uint8_t *val) {
+    auto field_offset = GetOptionalFieldOffset(field);
+    if (!field_offset) return false;
+    WriteScalar(data_ + field_offset,
+                static_cast<uoffset_t>(val - (data_ + field_offset)));
+    return true;
+  }
+
+  uint8_t *GetAddressOf(voffset_t field) {
+    auto field_offset = GetOptionalFieldOffset(field);
+    return field_offset ? data_ + field_offset : nullptr;
+  }
+  const uint8_t *GetAddressOf(voffset_t field) const {
+    return const_cast<Table *>(this)->GetAddressOf(field);
+  }
+
+  bool CheckField(voffset_t field) const {
+    return GetOptionalFieldOffset(field) != 0;
+  }
+
+  // Verify the vtable of this table.
+  // Call this once per table, followed by VerifyField once per field.
+  bool VerifyTableStart(Verifier &verifier) const {
+    return verifier.VerifyTableStart(data_);
+  }
+
+  // Verify a particular field.
+  template<typename T>
+  bool VerifyField(const Verifier &verifier, voffset_t field) const {
+    // Calling GetOptionalFieldOffset should be safe now thanks to
+    // VerifyTable().
+    auto field_offset = GetOptionalFieldOffset(field);
+    // Check the actual field.
+    return !field_offset || verifier.Verify<T>(data_, field_offset);
+  }
+
+  // VerifyField for required fields.
+  template<typename T>
+  bool VerifyFieldRequired(const Verifier &verifier, voffset_t field) const {
+    auto field_offset = GetOptionalFieldOffset(field);
+    return verifier.Check(field_offset != 0) &&
+           verifier.Verify<T>(data_, field_offset);
+  }
+
+  // Versions for offsets.
+  bool VerifyOffset(const Verifier &verifier, voffset_t field) const {
+    auto field_offset = GetOptionalFieldOffset(field);
+    return !field_offset || verifier.VerifyOffset(data_, field_offset);
+  }
+
+  bool VerifyOffsetRequired(const Verifier &verifier, voffset_t field) const {
+    auto field_offset = GetOptionalFieldOffset(field);
+    return verifier.Check(field_offset != 0) &&
+           verifier.VerifyOffset(data_, field_offset);
+  }
+
+ private:
+  // private constructor & copy constructor: you obtain instances of this
+  // class by pointing to existing data only
+  Table();
+  Table(const Table &other);
+  Table &operator=(const Table &);
+
+  uint8_t data_[1];
+};
+
+// This specialization allows avoiding warnings like:
+// MSVC C4800: type: forcing value to bool 'true' or 'false'.
+template<>
+inline flatbuffers::Optional<bool> Table::GetOptional<uint8_t, bool>(
+    voffset_t field) const {
+  auto field_offset = GetOptionalFieldOffset(field);
+  auto p = data_ + field_offset;
+  return field_offset ? Optional<bool>(ReadScalar<uint8_t>(p) != 0)
+                      : Optional<bool>();
+}
+
+}  // namespace flatbuffers
+
+#endif  // FLATBUFFERS_TABLE_H_
\ No newline at end of file
diff --git a/include/flatbuffers/vector.h b/include/flatbuffers/vector.h
new file mode 100644
index 00000000..55feb0e0
--- /dev/null
+++ b/include/flatbuffers/vector.h
@@ -0,0 +1,376 @@
+/*
+ * Copyright 2021 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FLATBUFFERS_VECTOR_H_
+#define FLATBUFFERS_VECTOR_H_
+
+#include "flatbuffers/base.h"
+#include "flatbuffers/buffer.h"
+
+namespace flatbuffers {
+
+struct String;
+
+// An STL compatible iterator implementation for Vector below, effectively
+// calling Get() for every element.
+template<typename T, typename IT> struct VectorIterator {
+  typedef std::random_access_iterator_tag iterator_category;
+  typedef IT value_type;
+  typedef ptrdiff_t difference_type;
+  typedef IT *pointer;
+  typedef IT &reference;
+
+  VectorIterator(const uint8_t *data, uoffset_t i)
+      : data_(data + IndirectHelper<T>::element_stride * i) {}
+  VectorIterator(const VectorIterator &other) : data_(other.data_) {}
+  VectorIterator() : data_(nullptr) {}
+
+  VectorIterator &operator=(const VectorIterator &other) {
+    data_ = other.data_;
+    return *this;
+  }
+
+  // clang-format off
+  #if !defined(FLATBUFFERS_CPP98_STL)
+  VectorIterator &operator=(VectorIterator &&other) {
+    data_ = other.data_;
+    return *this;
+  }
+  #endif  // !defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+
+  bool operator==(const VectorIterator &other) const {
+    return data_ == other.data_;
+  }
+
+  bool operator<(const VectorIterator &other) const {
+    return data_ < other.data_;
+  }
+
+  bool operator!=(const VectorIterator &other) const {
+    return data_ != other.data_;
+  }
+
+  difference_type operator-(const VectorIterator &other) const {
+    return (data_ - other.data_) / IndirectHelper<T>::element_stride;
+  }
+
+  // Note: return type is incompatible with the standard
+  // `reference operator*()`.
+  IT operator*() const { return IndirectHelper<T>::Read(data_, 0); }
+
+  // Note: return type is incompatible with the standard
+  // `pointer operator->()`.
+  IT operator->() const { return IndirectHelper<T>::Read(data_, 0); }
+
+  VectorIterator &operator++() {
+    data_ += IndirectHelper<T>::element_stride;
+    return *this;
+  }
+
+  VectorIterator operator++(int) {
+    VectorIterator temp(data_, 0);
+    data_ += IndirectHelper<T>::element_stride;
+    return temp;
+  }
+
+  VectorIterator operator+(const uoffset_t &offset) const {
+    return VectorIterator(data_ + offset * IndirectHelper<T>::element_stride,
+                          0);
+  }
+
+  VectorIterator &operator+=(const uoffset_t &offset) {
+    data_ += offset * IndirectHelper<T>::element_stride;
+    return *this;
+  }
+
+  VectorIterator &operator--() {
+    data_ -= IndirectHelper<T>::element_stride;
+    return *this;
+  }
+
+  VectorIterator operator--(int) {
+    VectorIterator temp(data_, 0);
+    data_ -= IndirectHelper<T>::element_stride;
+    return temp;
+  }
+
+  VectorIterator operator-(const uoffset_t &offset) const {
+    return VectorIterator(data_ - offset * IndirectHelper<T>::element_stride,
+                          0);
+  }
+
+  VectorIterator &operator-=(const uoffset_t &offset) {
+    data_ -= offset * IndirectHelper<T>::element_stride;
+    return *this;
+  }
+
+ private:
+  const uint8_t *data_;
+};
+
+template<typename Iterator>
+struct VectorReverseIterator : public std::reverse_iterator<Iterator> {
+  explicit VectorReverseIterator(Iterator iter)
+      : std::reverse_iterator<Iterator>(iter) {}
+
+  // Note: return type is incompatible with the standard
+  // `reference operator*()`.
+  typename Iterator::value_type operator*() const {
+    auto tmp = std::reverse_iterator<Iterator>::current;
+    return *--tmp;
+  }
+
+  // Note: return type is incompatible with the standard
+  // `pointer operator->()`.
+  typename Iterator::value_type operator->() const {
+    auto tmp = std::reverse_iterator<Iterator>::current;
+    return *--tmp;
+  }
+};
+
+// This is used as a helper type for accessing vectors.
+// Vector::data() assumes the vector elements start after the length field.
+template<typename T> class Vector {
+ public:
+  typedef VectorIterator<T, typename IndirectHelper<T>::mutable_return_type>
+      iterator;
+  typedef VectorIterator<T, typename IndirectHelper<T>::return_type>
+      const_iterator;
+  typedef VectorReverseIterator<iterator> reverse_iterator;
+  typedef VectorReverseIterator<const_iterator> const_reverse_iterator;
+
+  typedef typename flatbuffers::bool_constant<flatbuffers::is_scalar<T>::value>
+      scalar_tag;
+
+  static FLATBUFFERS_CONSTEXPR bool is_span_observable =
+      scalar_tag::value && (FLATBUFFERS_LITTLEENDIAN || sizeof(T) == 1);
+
+  uoffset_t size() const { return EndianScalar(length_); }
+
+  // Deprecated: use size(). Here for backwards compatibility.
+  FLATBUFFERS_ATTRIBUTE(deprecated("use size() instead"))
+  uoffset_t Length() const { return size(); }
+
+  typedef typename IndirectHelper<T>::return_type return_type;
+  typedef typename IndirectHelper<T>::mutable_return_type mutable_return_type;
+  typedef return_type value_type;
+
+  return_type Get(uoffset_t i) const {
+    FLATBUFFERS_ASSERT(i < size());
+    return IndirectHelper<T>::Read(Data(), i);
+  }
+
+  return_type operator[](uoffset_t i) const { return Get(i); }
+
+  // If this is a Vector of enums, T will be its storage type, not the enum
+  // type. This function makes it convenient to retrieve value with enum
+  // type E.
+  template<typename E> E GetEnum(uoffset_t i) const {
+    return static_cast<E>(Get(i));
+  }
+
+  // If this a vector of unions, this does the cast for you. There's no check
+  // to make sure this is the right type!
+  template<typename U> const U *GetAs(uoffset_t i) const {
+    return reinterpret_cast<const U *>(Get(i));
+  }
+
+  // If this a vector of unions, this does the cast for you. There's no check
+  // to make sure this is actually a string!
+  const String *GetAsString(uoffset_t i) const {
+    return reinterpret_cast<const String *>(Get(i));
+  }
+
+  const void *GetStructFromOffset(size_t o) const {
+    return reinterpret_cast<const void *>(Data() + o);
+  }
+
+  iterator begin() { return iterator(Data(), 0); }
+  const_iterator begin() const { return const_iterator(Data(), 0); }
+
+  iterator end() { return iterator(Data(), size()); }
+  const_iterator end() const { return const_iterator(Data(), size()); }
+
+  reverse_iterator rbegin() { return reverse_iterator(end()); }
+  const_reverse_iterator rbegin() const {
+    return const_reverse_iterator(end());
+  }
+
+  reverse_iterator rend() { return reverse_iterator(begin()); }
+  const_reverse_iterator rend() const {
+    return const_reverse_iterator(begin());
+  }
+
+  const_iterator cbegin() const { return begin(); }
+
+  const_iterator cend() const { return end(); }
+
+  const_reverse_iterator crbegin() const { return rbegin(); }
+
+  const_reverse_iterator crend() const { return rend(); }
+
+  // Change elements if you have a non-const pointer to this object.
+  // Scalars only. See reflection.h, and the documentation.
+  void Mutate(uoffset_t i, const T &val) {
+    FLATBUFFERS_ASSERT(i < size());
+    WriteScalar(data() + i, val);
+  }
+
+  // Change an element of a vector of tables (or strings).
+  // "val" points to the new table/string, as you can obtain from
+  // e.g. reflection::AddFlatBuffer().
+  void MutateOffset(uoffset_t i, const uint8_t *val) {
+    FLATBUFFERS_ASSERT(i < size());
+    static_assert(sizeof(T) == sizeof(uoffset_t), "Unrelated types");
+    WriteScalar(data() + i,
+                static_cast<uoffset_t>(val - (Data() + i * sizeof(uoffset_t))));
+  }
+
+  // Get a mutable pointer to tables/strings inside this vector.
+  mutable_return_type GetMutableObject(uoffset_t i) const {
+    FLATBUFFERS_ASSERT(i < size());
+    return const_cast<mutable_return_type>(IndirectHelper<T>::Read(Data(), i));
+  }
+
+  // The raw data in little endian format. Use with care.
+  const uint8_t *Data() const {
+    return reinterpret_cast<const uint8_t *>(&length_ + 1);
+  }
+
+  uint8_t *Data() { return reinterpret_cast<uint8_t *>(&length_ + 1); }
+
+  // Similarly, but typed, much like std::vector::data
+  const T *data() const { return reinterpret_cast<const T *>(Data()); }
+  T *data() { return reinterpret_cast<T *>(Data()); }
+
+  template<typename K> return_type LookupByKey(K key) const {
+    void *search_result = std::bsearch(
+        &key, Data(), size(), IndirectHelper<T>::element_stride, KeyCompare<K>);
+
+    if (!search_result) {
+      return nullptr;  // Key not found.
+    }
+
+    const uint8_t *element = reinterpret_cast<const uint8_t *>(search_result);
+
+    return IndirectHelper<T>::Read(element, 0);
+  }
+
+  template<typename K> mutable_return_type MutableLookupByKey(K key) {
+    return const_cast<mutable_return_type>(LookupByKey(key));
+  }
+
+ protected:
+  // This class is only used to access pre-existing data. Don't ever
+  // try to construct these manually.
+  Vector();
+
+  uoffset_t length_;
+
+ private:
+  // This class is a pointer. Copying will therefore create an invalid object.
+  // Private and unimplemented copy constructor.
+  Vector(const Vector &);
+  Vector &operator=(const Vector &);
+
+  template<typename K> static int KeyCompare(const void *ap, const void *bp) {
+    const K *key = reinterpret_cast<const K *>(ap);
+    const uint8_t *data = reinterpret_cast<const uint8_t *>(bp);
+    auto table = IndirectHelper<T>::Read(data, 0);
+
+    // std::bsearch compares with the operands transposed, so we negate the
+    // result here.
+    return -table->KeyCompareWithValue(*key);
+  }
+};
+
+template<class U>
+FLATBUFFERS_CONSTEXPR_CPP11 flatbuffers::span<U> make_span(Vector<U> &vec)
+    FLATBUFFERS_NOEXCEPT {
+  static_assert(Vector<U>::is_span_observable,
+                "wrong type U, only LE-scalar, or byte types are allowed");
+  return span<U>(vec.data(), vec.size());
+}
+
+template<class U>
+FLATBUFFERS_CONSTEXPR_CPP11 flatbuffers::span<const U> make_span(
+    const Vector<U> &vec) FLATBUFFERS_NOEXCEPT {
+  static_assert(Vector<U>::is_span_observable,
+                "wrong type U, only LE-scalar, or byte types are allowed");
+  return span<const U>(vec.data(), vec.size());
+}
+
+template<class U>
+FLATBUFFERS_CONSTEXPR_CPP11 flatbuffers::span<uint8_t> make_bytes_span(
+    Vector<U> &vec) FLATBUFFERS_NOEXCEPT {
+  static_assert(Vector<U>::scalar_tag::value,
+                "wrong type U, only LE-scalar, or byte types are allowed");
+  return span<uint8_t>(vec.Data(), vec.size() * sizeof(U));
+}
+
+template<class U>
+FLATBUFFERS_CONSTEXPR_CPP11 flatbuffers::span<const uint8_t> make_bytes_span(
+    const Vector<U> &vec) FLATBUFFERS_NOEXCEPT {
+  static_assert(Vector<U>::scalar_tag::value,
+                "wrong type U, only LE-scalar, or byte types are allowed");
+  return span<const uint8_t>(vec.Data(), vec.size() * sizeof(U));
+}
+
+// Represent a vector much like the template above, but in this case we
+// don't know what the element types are (used with reflection.h).
+class VectorOfAny {
+ public:
+  uoffset_t size() const { return EndianScalar(length_); }
+
+  const uint8_t *Data() const {
+    return reinterpret_cast<const uint8_t *>(&length_ + 1);
+  }
+  uint8_t *Data() { return reinterpret_cast<uint8_t *>(&length_ + 1); }
+
+ protected:
+  VectorOfAny();
+
+  uoffset_t length_;
+
+ private:
+  VectorOfAny(const VectorOfAny &);
+  VectorOfAny &operator=(const VectorOfAny &);
+};
+
+#ifndef FLATBUFFERS_CPP98_STL
+template<typename T, typename U>
+Vector<Offset<T>> *VectorCast(Vector<Offset<U>> *ptr) {
+  static_assert(std::is_base_of<T, U>::value, "Unrelated types");
+  return reinterpret_cast<Vector<Offset<T>> *>(ptr);
+}
+
+template<typename T, typename U>
+const Vector<Offset<T>> *VectorCast(const Vector<Offset<U>> *ptr) {
+  static_assert(std::is_base_of<T, U>::value, "Unrelated types");
+  return reinterpret_cast<const Vector<Offset<T>> *>(ptr);
+}
+#endif
+
+// Convenient helper function to get the length of any vector, regardless
+// of whether it is null or not (the field is not set).
+template<typename T> static inline size_t VectorLength(const Vector<T> *v) {
+  return v ? v->size() : 0;
+}
+
+}  // namespace flatbuffers
+
+#endif  // FLATBUFFERS_VERIFIER_H_
diff --git a/include/flatbuffers/vector_downward.h b/include/flatbuffers/vector_downward.h
new file mode 100644
index 00000000..d507134c
--- /dev/null
+++ b/include/flatbuffers/vector_downward.h
@@ -0,0 +1,272 @@
+/*
+ * Copyright 2021 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FLATBUFFERS_VECTOR_DOWNWARD_H_
+#define FLATBUFFERS_VECTOR_DOWNWARD_H_
+
+#include "flatbuffers/base.h"
+#include "flatbuffers/default_allocator.h"
+#include "flatbuffers/detached_buffer.h"
+
+namespace flatbuffers {
+
+// This is a minimal replication of std::vector<uint8_t> functionality,
+// except growing from higher to lower addresses. i.e push_back() inserts data
+// in the lowest address in the vector.
+// Since this vector leaves the lower part unused, we support a "scratch-pad"
+// that can be stored there for temporary data, to share the allocated space.
+// Essentially, this supports 2 std::vectors in a single buffer.
+class vector_downward {
+ public:
+  explicit vector_downward(size_t initial_size, Allocator *allocator,
+                           bool own_allocator, size_t buffer_minalign)
+      : allocator_(allocator),
+        own_allocator_(own_allocator),
+        initial_size_(initial_size),
+        buffer_minalign_(buffer_minalign),
+        reserved_(0),
+        buf_(nullptr),
+        cur_(nullptr),
+        scratch_(nullptr) {}
+
+  // clang-format off
+  #if !defined(FLATBUFFERS_CPP98_STL)
+  vector_downward(vector_downward &&other)
+  #else
+  vector_downward(vector_downward &other)
+  #endif  // defined(FLATBUFFERS_CPP98_STL)
+      // clang-format on
+      : allocator_(other.allocator_),
+        own_allocator_(other.own_allocator_),
+        initial_size_(other.initial_size_),
+        buffer_minalign_(other.buffer_minalign_),
+        reserved_(other.reserved_),
+        buf_(other.buf_),
+        cur_(other.cur_),
+        scratch_(other.scratch_) {
+    // No change in other.allocator_
+    // No change in other.initial_size_
+    // No change in other.buffer_minalign_
+    other.own_allocator_ = false;
+    other.reserved_ = 0;
+    other.buf_ = nullptr;
+    other.cur_ = nullptr;
+    other.scratch_ = nullptr;
+  }
+
+  // clang-format off
+  #if !defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+  vector_downward &operator=(vector_downward &&other) {
+    // Move construct a temporary and swap idiom
+    vector_downward temp(std::move(other));
+    swap(temp);
+    return *this;
+  }
+  // clang-format off
+  #endif  // defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+
+  ~vector_downward() {
+    clear_buffer();
+    clear_allocator();
+  }
+
+  void reset() {
+    clear_buffer();
+    clear();
+  }
+
+  void clear() {
+    if (buf_) {
+      cur_ = buf_ + reserved_;
+    } else {
+      reserved_ = 0;
+      cur_ = nullptr;
+    }
+    clear_scratch();
+  }
+
+  void clear_scratch() { scratch_ = buf_; }
+
+  void clear_allocator() {
+    if (own_allocator_ && allocator_) { delete allocator_; }
+    allocator_ = nullptr;
+    own_allocator_ = false;
+  }
+
+  void clear_buffer() {
+    if (buf_) Deallocate(allocator_, buf_, reserved_);
+    buf_ = nullptr;
+  }
+
+  // Relinquish the pointer to the caller.
+  uint8_t *release_raw(size_t &allocated_bytes, size_t &offset) {
+    auto *buf = buf_;
+    allocated_bytes = reserved_;
+    offset = static_cast<size_t>(cur_ - buf_);
+
+    // release_raw only relinquishes the buffer ownership.
+    // Does not deallocate or reset the allocator. Destructor will do that.
+    buf_ = nullptr;
+    clear();
+    return buf;
+  }
+
+  // Relinquish the pointer to the caller.
+  DetachedBuffer release() {
+    // allocator ownership (if any) is transferred to DetachedBuffer.
+    DetachedBuffer fb(allocator_, own_allocator_, buf_, reserved_, cur_,
+                      size());
+    if (own_allocator_) {
+      allocator_ = nullptr;
+      own_allocator_ = false;
+    }
+    buf_ = nullptr;
+    clear();
+    return fb;
+  }
+
+  size_t ensure_space(size_t len) {
+    FLATBUFFERS_ASSERT(cur_ >= scratch_ && scratch_ >= buf_);
+    if (len > static_cast<size_t>(cur_ - scratch_)) { reallocate(len); }
+    // Beyond this, signed offsets may not have enough range:
+    // (FlatBuffers > 2GB not supported).
+    FLATBUFFERS_ASSERT(size() < FLATBUFFERS_MAX_BUFFER_SIZE);
+    return len;
+  }
+
+  inline uint8_t *make_space(size_t len) {
+    size_t space = ensure_space(len);
+    cur_ -= space;
+    return cur_;
+  }
+
+  // Returns nullptr if using the DefaultAllocator.
+  Allocator *get_custom_allocator() { return allocator_; }
+
+  uoffset_t size() const {
+    return static_cast<uoffset_t>(reserved_ - static_cast<size_t>(cur_ - buf_));
+  }
+
+  uoffset_t scratch_size() const {
+    return static_cast<uoffset_t>(scratch_ - buf_);
+  }
+
+  size_t capacity() const { return reserved_; }
+
+  uint8_t *data() const {
+    FLATBUFFERS_ASSERT(cur_);
+    return cur_;
+  }
+
+  uint8_t *scratch_data() const {
+    FLATBUFFERS_ASSERT(buf_);
+    return buf_;
+  }
+
+  uint8_t *scratch_end() const {
+    FLATBUFFERS_ASSERT(scratch_);
+    return scratch_;
+  }
+
+  uint8_t *data_at(size_t offset) const { return buf_ + reserved_ - offset; }
+
+  void push(const uint8_t *bytes, size_t num) {
+    if (num > 0) { memcpy(make_space(num), bytes, num); }
+  }
+
+  // Specialized version of push() that avoids memcpy call for small data.
+  template<typename T> void push_small(const T &little_endian_t) {
+    make_space(sizeof(T));
+    *reinterpret_cast<T *>(cur_) = little_endian_t;
+  }
+
+  template<typename T> void scratch_push_small(const T &t) {
+    ensure_space(sizeof(T));
+    *reinterpret_cast<T *>(scratch_) = t;
+    scratch_ += sizeof(T);
+  }
+
+  // fill() is most frequently called with small byte counts (<= 4),
+  // which is why we're using loops rather than calling memset.
+  void fill(size_t zero_pad_bytes) {
+    make_space(zero_pad_bytes);
+    for (size_t i = 0; i < zero_pad_bytes; i++) cur_[i] = 0;
+  }
+
+  // Version for when we know the size is larger.
+  // Precondition: zero_pad_bytes > 0
+  void fill_big(size_t zero_pad_bytes) {
+    memset(make_space(zero_pad_bytes), 0, zero_pad_bytes);
+  }
+
+  void pop(size_t bytes_to_remove) { cur_ += bytes_to_remove; }
+  void scratch_pop(size_t bytes_to_remove) { scratch_ -= bytes_to_remove; }
+
+  void swap(vector_downward &other) {
+    using std::swap;
+    swap(allocator_, other.allocator_);
+    swap(own_allocator_, other.own_allocator_);
+    swap(initial_size_, other.initial_size_);
+    swap(buffer_minalign_, other.buffer_minalign_);
+    swap(reserved_, other.reserved_);
+    swap(buf_, other.buf_);
+    swap(cur_, other.cur_);
+    swap(scratch_, other.scratch_);
+  }
+
+  void swap_allocator(vector_downward &other) {
+    using std::swap;
+    swap(allocator_, other.allocator_);
+    swap(own_allocator_, other.own_allocator_);
+  }
+
+ private:
+  // You shouldn't really be copying instances of this class.
+  FLATBUFFERS_DELETE_FUNC(vector_downward(const vector_downward &));
+  FLATBUFFERS_DELETE_FUNC(vector_downward &operator=(const vector_downward &));
+
+  Allocator *allocator_;
+  bool own_allocator_;
+  size_t initial_size_;
+  size_t buffer_minalign_;
+  size_t reserved_;
+  uint8_t *buf_;
+  uint8_t *cur_;  // Points at location between empty (below) and used (above).
+  uint8_t *scratch_;  // Points to the end of the scratchpad in use.
+
+  void reallocate(size_t len) {
+    auto old_reserved = reserved_;
+    auto old_size = size();
+    auto old_scratch_size = scratch_size();
+    reserved_ +=
+        (std::max)(len, old_reserved ? old_reserved / 2 : initial_size_);
+    reserved_ = (reserved_ + buffer_minalign_ - 1) & ~(buffer_minalign_ - 1);
+    if (buf_) {
+      buf_ = ReallocateDownward(allocator_, buf_, old_reserved, reserved_,
+                                old_size, old_scratch_size);
+    } else {
+      buf_ = Allocate(allocator_, reserved_);
+    }
+    cur_ = buf_ + reserved_ - old_size;
+    scratch_ = buf_ + old_scratch_size;
+  }
+};
+
+}  // namespace flatbuffers
+
+#endif  // FLATBUFFERS_VECTOR_DOWNWARD_H_
\ No newline at end of file
diff --git a/include/flatbuffers/verifier.h b/include/flatbuffers/verifier.h
new file mode 100644
index 00000000..8d99dc64
--- /dev/null
+++ b/include/flatbuffers/verifier.h
@@ -0,0 +1,262 @@
+/*
+ * Copyright 2021 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FLATBUFFERS_VERIFIER_H_
+#define FLATBUFFERS_VERIFIER_H_
+
+#include "flatbuffers/base.h"
+#include "flatbuffers/util.h"
+#include "flatbuffers/vector.h"
+
+namespace flatbuffers {
+
+// Helper class to verify the integrity of a FlatBuffer
+class Verifier FLATBUFFERS_FINAL_CLASS {
+ public:
+  Verifier(const uint8_t *buf, size_t buf_len, uoffset_t _max_depth = 64,
+           uoffset_t _max_tables = 1000000, bool _check_alignment = true)
+      : buf_(buf),
+        size_(buf_len),
+        depth_(0),
+        max_depth_(_max_depth),
+        num_tables_(0),
+        max_tables_(_max_tables),
+        upper_bound_(0),
+        check_alignment_(_check_alignment) {
+    FLATBUFFERS_ASSERT(size_ < FLATBUFFERS_MAX_BUFFER_SIZE);
+  }
+
+  // Central location where any verification failures register.
+  bool Check(bool ok) const {
+    // clang-format off
+    #ifdef FLATBUFFERS_DEBUG_VERIFICATION_FAILURE
+      FLATBUFFERS_ASSERT(ok);
+    #endif
+    #ifdef FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE
+      if (!ok)
+        upper_bound_ = 0;
+    #endif
+    // clang-format on
+    return ok;
+  }
+
+  // Verify any range within the buffer.
+  bool Verify(size_t elem, size_t elem_len) const {
+    // clang-format off
+    #ifdef FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE
+      auto upper_bound = elem + elem_len;
+      if (upper_bound_ < upper_bound)
+        upper_bound_ =  upper_bound;
+    #endif
+    // clang-format on
+    return Check(elem_len < size_ && elem <= size_ - elem_len);
+  }
+
+  template<typename T> bool VerifyAlignment(size_t elem) const {
+    return Check((elem & (sizeof(T) - 1)) == 0 || !check_alignment_);
+  }
+
+  // Verify a range indicated by sizeof(T).
+  template<typename T> bool Verify(size_t elem) const {
+    return VerifyAlignment<T>(elem) && Verify(elem, sizeof(T));
+  }
+
+  bool VerifyFromPointer(const uint8_t *p, size_t len) {
+    auto o = static_cast<size_t>(p - buf_);
+    return Verify(o, len);
+  }
+
+  // Verify relative to a known-good base pointer.
+  bool Verify(const uint8_t *base, voffset_t elem_off, size_t elem_len) const {
+    return Verify(static_cast<size_t>(base - buf_) + elem_off, elem_len);
+  }
+
+  template<typename T>
+  bool Verify(const uint8_t *base, voffset_t elem_off) const {
+    return Verify(static_cast<size_t>(base - buf_) + elem_off, sizeof(T));
+  }
+
+  // Verify a pointer (may be NULL) of a table type.
+  template<typename T> bool VerifyTable(const T *table) {
+    return !table || table->Verify(*this);
+  }
+
+  // Verify a pointer (may be NULL) of any vector type.
+  template<typename T> bool VerifyVector(const Vector<T> *vec) const {
+    return !vec || VerifyVectorOrString(reinterpret_cast<const uint8_t *>(vec),
+                                        sizeof(T));
+  }
+
+  // Verify a pointer (may be NULL) of a vector to struct.
+  template<typename T> bool VerifyVector(const Vector<const T *> *vec) const {
+    return VerifyVector(reinterpret_cast<const Vector<T> *>(vec));
+  }
+
+  // Verify a pointer (may be NULL) to string.
+  bool VerifyString(const String *str) const {
+    size_t end;
+    return !str || (VerifyVectorOrString(reinterpret_cast<const uint8_t *>(str),
+                                         1, &end) &&
+                    Verify(end, 1) &&           // Must have terminator
+                    Check(buf_[end] == '\0'));  // Terminating byte must be 0.
+  }
+
+  // Common code between vectors and strings.
+  bool VerifyVectorOrString(const uint8_t *vec, size_t elem_size,
+                            size_t *end = nullptr) const {
+    auto veco = static_cast<size_t>(vec - buf_);
+    // Check we can read the size field.
+    if (!Verify<uoffset_t>(veco)) return false;
+    // Check the whole array. If this is a string, the byte past the array
+    // must be 0.
+    auto size = ReadScalar<uoffset_t>(vec);
+    auto max_elems = FLATBUFFERS_MAX_BUFFER_SIZE / elem_size;
+    if (!Check(size < max_elems))
+      return false;  // Protect against byte_size overflowing.
+    auto byte_size = sizeof(size) + elem_size * size;
+    if (end) *end = veco + byte_size;
+    return Verify(veco, byte_size);
+  }
+
+  // Special case for string contents, after the above has been called.
+  bool VerifyVectorOfStrings(const Vector<Offset<String>> *vec) const {
+    if (vec) {
+      for (uoffset_t i = 0; i < vec->size(); i++) {
+        if (!VerifyString(vec->Get(i))) return false;
+      }
+    }
+    return true;
+  }
+
+  // Special case for table contents, after the above has been called.
+  template<typename T> bool VerifyVectorOfTables(const Vector<Offset<T>> *vec) {
+    if (vec) {
+      for (uoffset_t i = 0; i < vec->size(); i++) {
+        if (!vec->Get(i)->Verify(*this)) return false;
+      }
+    }
+    return true;
+  }
+
+  __supress_ubsan__("unsigned-integer-overflow") bool VerifyTableStart(
+      const uint8_t *table) {
+    // Check the vtable offset.
+    auto tableo = static_cast<size_t>(table - buf_);
+    if (!Verify<soffset_t>(tableo)) return false;
+    // This offset may be signed, but doing the subtraction unsigned always
+    // gives the result we want.
+    auto vtableo = tableo - static_cast<size_t>(ReadScalar<soffset_t>(table));
+    // Check the vtable size field, then check vtable fits in its entirety.
+    return VerifyComplexity() && Verify<voffset_t>(vtableo) &&
+           VerifyAlignment<voffset_t>(ReadScalar<voffset_t>(buf_ + vtableo)) &&
+           Verify(vtableo, ReadScalar<voffset_t>(buf_ + vtableo));
+  }
+
+  template<typename T>
+  bool VerifyBufferFromStart(const char *identifier, size_t start) {
+    if (identifier && !Check((size_ >= 2 * sizeof(flatbuffers::uoffset_t) &&
+                              BufferHasIdentifier(buf_ + start, identifier)))) {
+      return false;
+    }
+
+    // Call T::Verify, which must be in the generated code for this type.
+    auto o = VerifyOffset(start);
+    return o && reinterpret_cast<const T *>(buf_ + start + o)->Verify(*this)
+    // clang-format off
+    #ifdef FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE
+           && GetComputedSize()
+    #endif
+        ;
+    // clang-format on
+  }
+
+  // Verify this whole buffer, starting with root type T.
+  template<typename T> bool VerifyBuffer() { return VerifyBuffer<T>(nullptr); }
+
+  template<typename T> bool VerifyBuffer(const char *identifier) {
+    return VerifyBufferFromStart<T>(identifier, 0);
+  }
+
+  template<typename T> bool VerifySizePrefixedBuffer(const char *identifier) {
+    return Verify<uoffset_t>(0U) &&
+           ReadScalar<uoffset_t>(buf_) == size_ - sizeof(uoffset_t) &&
+           VerifyBufferFromStart<T>(identifier, sizeof(uoffset_t));
+  }
+
+  uoffset_t VerifyOffset(size_t start) const {
+    if (!Verify<uoffset_t>(start)) return 0;
+    auto o = ReadScalar<uoffset_t>(buf_ + start);
+    // May not point to itself.
+    if (!Check(o != 0)) return 0;
+    // Can't wrap around / buffers are max 2GB.
+    if (!Check(static_cast<soffset_t>(o) >= 0)) return 0;
+    // Must be inside the buffer to create a pointer from it (pointer outside
+    // buffer is UB).
+    if (!Verify(start + o, 1)) return 0;
+    return o;
+  }
+
+  uoffset_t VerifyOffset(const uint8_t *base, voffset_t start) const {
+    return VerifyOffset(static_cast<size_t>(base - buf_) + start);
+  }
+
+  // Called at the start of a table to increase counters measuring data
+  // structure depth and amount, and possibly bails out with false if
+  // limits set by the constructor have been hit. Needs to be balanced
+  // with EndTable().
+  bool VerifyComplexity() {
+    depth_++;
+    num_tables_++;
+    return Check(depth_ <= max_depth_ && num_tables_ <= max_tables_);
+  }
+
+  // Called at the end of a table to pop the depth count.
+  bool EndTable() {
+    depth_--;
+    return true;
+  }
+
+  // Returns the message size in bytes
+  size_t GetComputedSize() const {
+    // clang-format off
+    #ifdef FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE
+      uintptr_t size = upper_bound_;
+      // Align the size to uoffset_t
+      size = (size - 1 + sizeof(uoffset_t)) & ~(sizeof(uoffset_t) - 1);
+      return (size > size_) ?  0 : size;
+    #else
+      // Must turn on FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE for this to work.
+      (void)upper_bound_;
+      FLATBUFFERS_ASSERT(false);
+      return 0;
+    #endif
+    // clang-format on
+  }
+
+ private:
+  const uint8_t *buf_;
+  size_t size_;
+  uoffset_t depth_;
+  uoffset_t max_depth_;
+  uoffset_t num_tables_;
+  uoffset_t max_tables_;
+  mutable size_t upper_bound_;
+  bool check_alignment_;
+};
+
+}  // namespace flatbuffers
+
+#endif  // FLATBUFFERS_VERIFIER_H_
diff --git a/src/idl_parser.cpp b/src/idl_parser.cpp
index f100a6a9..328d8dcb 100644
--- a/src/idl_parser.cpp
+++ b/src/idl_parser.cpp
@@ -20,6 +20,7 @@
 #include <string>
 #include <utility>
 
+#include "flatbuffers/base.h"
 #include "flatbuffers/idl.h"
 #include "flatbuffers/util.h"
 
@@ -3404,9 +3405,9 @@ CheckedError Parser::DoParse(const char *source, const char **include_paths,
       NEXT();
       file_identifier_ = attribute_;
       EXPECT(kTokenStringConstant);
-      if (file_identifier_.length() != FlatBufferBuilder::kFileIdentifierLength)
+      if (file_identifier_.length() != flatbuffers::kFileIdentifierLength)
         return Error("file_identifier must be exactly " +
-                     NumToString(FlatBufferBuilder::kFileIdentifierLength) +
+                     NumToString(flatbuffers::kFileIdentifierLength) +
                      " characters");
       EXPECT(';');
     } else if (IsIdent("file_extension")) {
diff --git a/tests/fuzzer/CMakeLists.txt b/tests/fuzzer/CMakeLists.txt
index e57343b2..e23a1055 100644
--- a/tests/fuzzer/CMakeLists.txt
+++ b/tests/fuzzer/CMakeLists.txt
@@ -85,17 +85,30 @@ target_link_libraries(
 set(FLATBUFFERS_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../../")
 
 set(FlatBuffers_Library_SRCS
+    ${FLATBUFFERS_DIR}/include/flatbuffers/allocator.h
+    ${FLATBUFFERS_DIR}/include/flatbuffers/array.h
     ${FLATBUFFERS_DIR}/include/flatbuffers/base.h
+    ${FLATBUFFERS_DIR}/include/flatbuffer/buffer.h
+    ${FLATBUFFERS_DIR}/include/flatbuffers/buffer_ref.h
+    ${FLATBUFFERS_DIR}/include/flatbuffers/default_allocator.h
+    ${FLATBUFFERS_DIR}/include/flatbuffers/detached_buffer.h
+    ${FLATBUFFERS_DIR}/include/flatbuffers/flatbuffer_builder.h
     ${FLATBUFFERS_DIR}/include/flatbuffers/flatbuffers.h
+    ${FLATBUFFERS_DIR}/include/flatbuffers/flexbuffers.h
     ${FLATBUFFERS_DIR}/include/flatbuffers/hash.h
     ${FLATBUFFERS_DIR}/include/flatbuffers/idl.h
-    ${FLATBUFFERS_DIR}/include/flatbuffers/util.h
+    ${FLATBUFFERS_DIR}/include/flatbuffers/minireflect.h
     ${FLATBUFFERS_DIR}/include/flatbuffers/reflection.h
     ${FLATBUFFERS_DIR}/include/flatbuffers/reflection_generated.h
-    ${FLATBUFFERS_DIR}/include/flatbuffers/stl_emulation.h
-    ${FLATBUFFERS_DIR}/include/flatbuffers/flexbuffers.h
     ${FLATBUFFERS_DIR}/include/flatbuffers/registry.h
-    ${FLATBUFFERS_DIR}/include/flatbuffers/minireflect.h
+    ${FLATBUFFERS_DIR}/include/flatbuffers/stl_emulation.h
+    ${FLATBUFFERS_DIR}/include/flatbuffers/string.h
+    ${FLATBUFFERS_DIR}/include/flatbuffers/struct.h
+    ${FLATBUFFERS_DIR}/include/flatbuffers/table.h
+    ${FLATBUFFERS_DIR}/include/flatbuffers/util.h
+    ${FLATBUFFERS_DIR}/include/flatbuffers/vector.h
+    ${FLATBUFFERS_DIR}/include/flatbuffers/vector_downward.h
+    ${FLATBUFFERS_DIR}/include/flatbuffers/verifier.h
     ${FLATBUFFERS_DIR}/src/idl_parser.cpp
     ${FLATBUFFERS_DIR}/src/idl_gen_text.cpp
     ${FLATBUFFERS_DIR}/src/reflection.cpp