FlatBuffers 64 for C++ (#7935)

* First working hack of adding 64-bit. Don't judge :)

* Made vector_downward work on 64 bit types

* vector_downward uses size_t, added offset64 to reflection

* cleaned up adding offset64 in parser

* Add C++ testing skeleton for 64-bit

* working test for CreateVector64

* working >2 GiB buffers

* support for large strings

* simplified CreateString<> to just provide the offset type

* generalize CreateVector template

* update test_64.afb due to upstream format change

* Added Vector64 type, which is just an alias for vector ATM

* Switch to Offset64 for Vector64

* Update for reflection bfbs output change

* Starting to add support for vector64 type in C++

* made a generic CreateVector that can handle different offsets and vector types

* Support for 32-vector with 64-addressing

* Vector64 basic builder + tests working

* basic support for json vector64 support

* renamed fields in test_64bit.fbs to better reflect their use

* working C++ vector64 builder

* Apply --annotate-sparse-vector to 64-bit tests

* Enable Vector64 for --annotate-sparse-vectors

* Merged from upstream

* Add `near_string` field for testing 32-bit offsets alongside

* keep track of where the 32-bit and 64-bit regions are for flatbufferbuilder

* move template<> outside class body for GCC

* update run.sh to build and run tests

* basic assertion for adding 64-bit offset at the wrong time

* started to separate `FlatBufferBuilder` into two classes, 1 64-bit aware, the other not

* add test for nested flatbuffer vector64, fix bug in alignment of big vectors

* fixed CreateDirect method by iterating by Offset64 first

* internal refactoring of flatbufferbuilder

* block not supported languages in the parser from using 64-bit

* evolution tests for adding a vector64 field

* conformity tests for adding/removing offset64 attributes

* ensure test is for a big buffer

* add parser error tests for `offset64` and `vector64` attributes

* add missing static that GCC only complains about

* remove stdint-uintn.h header that gets automatically added

* move 64-bit CalculateOffset internal

* fixed return size of EndVector

* various fixes on windows

* add SizeT to vector_downward

* minimze range of size changes in vector and builder

* reworked how tracking if 64-offsets are added

* Add ReturnT to EndVector

* small cleanups

* remove need for second Array definition

* combine IndirectHelpers into one definition

* started support for vector of struct

* Support for 32/64-vectors of structs + Offset64

* small cleanups

* add verification for vector64

* add sized prefix for 64-bit buffers

* add fuzzer for 64-bit

* add example of adding many vectors using a wrapper table

* run the new -bfbs-gen-embed logic on the 64-bit tests

* remove run.sh and fix cmakelist issue

* fixed bazel rules

* fixed some PR comments

* add 64-bit tests to cmakelist

24 files changed, 2039 insertions, 28 deletions

diff --git a/tests/64bit/evolution/v1.fbs b/tests/64bit/evolution/v1.fbs
new file mode 100644
index 00000000..dcdc0bad
--- /dev/null
+++ b/tests/64bit/evolution/v1.fbs
@@ -0,0 +1,8 @@
+namespace v1;
+
+table RootTable {
+  a:float;
+  b:[uint8];
+}
+
+root_type RootTable;
diff --git a/tests/64bit/evolution/v1_generated.h b/tests/64bit/evolution/v1_generated.h
new file mode 100644
index 00000000..49ed0f0e
--- /dev/null
+++ b/tests/64bit/evolution/v1_generated.h
@@ -0,0 +1,219 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+
+#ifndef FLATBUFFERS_GENERATED_V1_V1_H_
+#define FLATBUFFERS_GENERATED_V1_V1_H_
+
+#include "flatbuffers/flatbuffers.h"
+
+// Ensure the included flatbuffers.h is the same version as when this file was
+// generated, otherwise it may not be compatible.
+static_assert(FLATBUFFERS_VERSION_MAJOR == 23 &&
+              FLATBUFFERS_VERSION_MINOR == 5 &&
+              FLATBUFFERS_VERSION_REVISION == 8,
+             "Non-compatible flatbuffers version included");
+
+namespace v1 {
+
+struct RootTable;
+struct RootTableBuilder;
+struct RootTableT;
+
+bool operator==(const RootTableT &lhs, const RootTableT &rhs);
+bool operator!=(const RootTableT &lhs, const RootTableT &rhs);
+
+inline const ::flatbuffers::TypeTable *RootTableTypeTable();
+
+struct RootTableT : public ::flatbuffers::NativeTable {
+  typedef RootTable TableType;
+  float a = 0.0f;
+  std::vector<uint8_t> b{};
+};
+
+struct RootTable FLATBUFFERS_FINAL_CLASS : private ::flatbuffers::Table {
+  typedef RootTableT NativeTableType;
+  typedef RootTableBuilder Builder;
+  static const ::flatbuffers::TypeTable *MiniReflectTypeTable() {
+    return RootTableTypeTable();
+  }
+  enum FlatBuffersVTableOffset FLATBUFFERS_VTABLE_UNDERLYING_TYPE {
+    VT_A = 4,
+    VT_B = 6
+  };
+  float a() const {
+    return GetField<float>(VT_A, 0.0f);
+  }
+  bool mutate_a(float _a = 0.0f) {
+    return SetField<float>(VT_A, _a, 0.0f);
+  }
+  const ::flatbuffers::Vector<uint8_t> *b() const {
+    return GetPointer<const ::flatbuffers::Vector<uint8_t> *>(VT_B);
+  }
+  ::flatbuffers::Vector<uint8_t> *mutable_b() {
+    return GetPointer<::flatbuffers::Vector<uint8_t> *>(VT_B);
+  }
+  bool Verify(::flatbuffers::Verifier &verifier) const {
+    return VerifyTableStart(verifier) &&
+           VerifyField<float>(verifier, VT_A, 4) &&
+           VerifyOffset(verifier, VT_B) &&
+           verifier.VerifyVector(b()) &&
+           verifier.EndTable();
+  }
+  RootTableT *UnPack(const ::flatbuffers::resolver_function_t *_resolver = nullptr) const;
+  void UnPackTo(RootTableT *_o, const ::flatbuffers::resolver_function_t *_resolver = nullptr) const;
+  static ::flatbuffers::Offset<RootTable> Pack(::flatbuffers::FlatBufferBuilder &_fbb, const RootTableT* _o, const ::flatbuffers::rehasher_function_t *_rehasher = nullptr);
+};
+
+struct RootTableBuilder {
+  typedef RootTable Table;
+  ::flatbuffers::FlatBufferBuilder &fbb_;
+  ::flatbuffers::uoffset_t start_;
+  void add_a(float a) {
+    fbb_.AddElement<float>(RootTable::VT_A, a, 0.0f);
+  }
+  void add_b(::flatbuffers::Offset<::flatbuffers::Vector<uint8_t>> b) {
+    fbb_.AddOffset(RootTable::VT_B, b);
+  }
+  explicit RootTableBuilder(::flatbuffers::FlatBufferBuilder &_fbb)
+        : fbb_(_fbb) {
+    start_ = fbb_.StartTable();
+  }
+  ::flatbuffers::Offset<RootTable> Finish() {
+    const auto end = fbb_.EndTable(start_);
+    auto o = ::flatbuffers::Offset<RootTable>(end);
+    return o;
+  }
+};
+
+inline ::flatbuffers::Offset<RootTable> CreateRootTable(
+    ::flatbuffers::FlatBufferBuilder &_fbb,
+    float a = 0.0f,
+    ::flatbuffers::Offset<::flatbuffers::Vector<uint8_t>> b = 0) {
+  RootTableBuilder builder_(_fbb);
+  builder_.add_b(b);
+  builder_.add_a(a);
+  return builder_.Finish();
+}
+
+inline ::flatbuffers::Offset<RootTable> CreateRootTableDirect(
+    ::flatbuffers::FlatBufferBuilder &_fbb,
+    float a = 0.0f,
+    const std::vector<uint8_t> *b = nullptr) {
+  auto b__ = b ? _fbb.CreateVector<uint8_t>(*b) : 0;
+  return v1::CreateRootTable(
+      _fbb,
+      a,
+      b__);
+}
+
+::flatbuffers::Offset<RootTable> CreateRootTable(::flatbuffers::FlatBufferBuilder &_fbb, const RootTableT *_o, const ::flatbuffers::rehasher_function_t *_rehasher = nullptr);
+
+
+inline bool operator==(const RootTableT &lhs, const RootTableT &rhs) {
+  return
+      (lhs.a == rhs.a) &&
+      (lhs.b == rhs.b);
+}
+
+inline bool operator!=(const RootTableT &lhs, const RootTableT &rhs) {
+    return !(lhs == rhs);
+}
+
+
+inline RootTableT *RootTable::UnPack(const ::flatbuffers::resolver_function_t *_resolver) const {
+  auto _o = std::unique_ptr<RootTableT>(new RootTableT());
+  UnPackTo(_o.get(), _resolver);
+  return _o.release();
+}
+
+inline void RootTable::UnPackTo(RootTableT *_o, const ::flatbuffers::resolver_function_t *_resolver) const {
+  (void)_o;
+  (void)_resolver;
+  { auto _e = a(); _o->a = _e; }
+  { auto _e = b(); if (_e) { _o->b.resize(_e->size()); std::copy(_e->begin(), _e->end(), _o->b.begin()); } }
+}
+
+inline ::flatbuffers::Offset<RootTable> RootTable::Pack(::flatbuffers::FlatBufferBuilder &_fbb, const RootTableT* _o, const ::flatbuffers::rehasher_function_t *_rehasher) {
+  return CreateRootTable(_fbb, _o, _rehasher);
+}
+
+inline ::flatbuffers::Offset<RootTable> CreateRootTable(::flatbuffers::FlatBufferBuilder &_fbb, const RootTableT *_o, const ::flatbuffers::rehasher_function_t *_rehasher) {
+  (void)_rehasher;
+  (void)_o;
+  struct _VectorArgs { ::flatbuffers::FlatBufferBuilder *__fbb; const RootTableT* __o; const ::flatbuffers::rehasher_function_t *__rehasher; } _va = { &_fbb, _o, _rehasher}; (void)_va;
+  auto _a = _o->a;
+  auto _b = _o->b.size() ? _fbb.CreateVector(_o->b) : 0;
+  return v1::CreateRootTable(
+      _fbb,
+      _a,
+      _b);
+}
+
+inline const ::flatbuffers::TypeTable *RootTableTypeTable() {
+  static const ::flatbuffers::TypeCode type_codes[] = {
+    { ::flatbuffers::ET_FLOAT, 0, -1 },
+    { ::flatbuffers::ET_UCHAR, 1, -1 }
+  };
+  static const char * const names[] = {
+    "a",
+    "b"
+  };
+  static const ::flatbuffers::TypeTable tt = {
+    ::flatbuffers::ST_TABLE, 2, type_codes, nullptr, nullptr, nullptr, names
+  };
+  return &tt;
+}
+
+inline const v1::RootTable *GetRootTable(const void *buf) {
+  return ::flatbuffers::GetRoot<v1::RootTable>(buf);
+}
+
+inline const v1::RootTable *GetSizePrefixedRootTable(const void *buf) {
+  return ::flatbuffers::GetSizePrefixedRoot<v1::RootTable>(buf);
+}
+
+inline RootTable *GetMutableRootTable(void *buf) {
+  return ::flatbuffers::GetMutableRoot<RootTable>(buf);
+}
+
+inline v1::RootTable *GetMutableSizePrefixedRootTable(void *buf) {
+  return ::flatbuffers::GetMutableSizePrefixedRoot<v1::RootTable>(buf);
+}
+
+inline bool VerifyRootTableBuffer(
+    ::flatbuffers::Verifier &verifier) {
+  return verifier.VerifyBuffer<v1::RootTable>(nullptr);
+}
+
+inline bool VerifySizePrefixedRootTableBuffer(
+    ::flatbuffers::Verifier &verifier) {
+  return verifier.VerifySizePrefixedBuffer<v1::RootTable>(nullptr);
+}
+
+inline void FinishRootTableBuffer(
+    ::flatbuffers::FlatBufferBuilder &fbb,
+    ::flatbuffers::Offset<v1::RootTable> root) {
+  fbb.Finish(root);
+}
+
+inline void FinishSizePrefixedRootTableBuffer(
+    ::flatbuffers::FlatBufferBuilder &fbb,
+    ::flatbuffers::Offset<v1::RootTable> root) {
+  fbb.FinishSizePrefixed(root);
+}
+
+inline std::unique_ptr<v1::RootTableT> UnPackRootTable(
+    const void *buf,
+    const ::flatbuffers::resolver_function_t *res = nullptr) {
+  return std::unique_ptr<v1::RootTableT>(GetRootTable(buf)->UnPack(res));
+}
+
+inline std::unique_ptr<v1::RootTableT> UnPackSizePrefixedRootTable(
+    const void *buf,
+    const ::flatbuffers::resolver_function_t *res = nullptr) {
+  return std::unique_ptr<v1::RootTableT>(GetSizePrefixedRootTable(buf)->UnPack(res));
+}
+
+}  // namespace v1
+
+#endif  // FLATBUFFERS_GENERATED_V1_V1_H_
diff --git a/tests/64bit/evolution/v2.fbs b/tests/64bit/evolution/v2.fbs
new file mode 100644
index 00000000..f83e5109
--- /dev/null
+++ b/tests/64bit/evolution/v2.fbs
@@ -0,0 +1,9 @@
+namespace v2;
+
+table RootTable {
+  a:float;
+  b:[uint8];
+  big_vector:[uint8] (vector64);
+}
+
+root_type RootTable;
diff --git a/tests/64bit/evolution/v2_generated.h b/tests/64bit/evolution/v2_generated.h
new file mode 100644
index 00000000..a46847df
--- /dev/null
+++ b/tests/64bit/evolution/v2_generated.h
@@ -0,0 +1,243 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+
+#ifndef FLATBUFFERS_GENERATED_V2_V2_H_
+#define FLATBUFFERS_GENERATED_V2_V2_H_
+
+#include "flatbuffers/flatbuffers.h"
+
+// Ensure the included flatbuffers.h is the same version as when this file was
+// generated, otherwise it may not be compatible.
+static_assert(FLATBUFFERS_VERSION_MAJOR == 23 &&
+              FLATBUFFERS_VERSION_MINOR == 5 &&
+              FLATBUFFERS_VERSION_REVISION == 8,
+             "Non-compatible flatbuffers version included");
+
+namespace v2 {
+
+struct RootTable;
+struct RootTableBuilder;
+struct RootTableT;
+
+bool operator==(const RootTableT &lhs, const RootTableT &rhs);
+bool operator!=(const RootTableT &lhs, const RootTableT &rhs);
+
+inline const ::flatbuffers::TypeTable *RootTableTypeTable();
+
+struct RootTableT : public ::flatbuffers::NativeTable {
+  typedef RootTable TableType;
+  float a = 0.0f;
+  std::vector<uint8_t> b{};
+  std::vector<uint8_t> big_vector{};
+};
+
+struct RootTable FLATBUFFERS_FINAL_CLASS : private ::flatbuffers::Table {
+  typedef RootTableT NativeTableType;
+  typedef RootTableBuilder Builder;
+  static const ::flatbuffers::TypeTable *MiniReflectTypeTable() {
+    return RootTableTypeTable();
+  }
+  enum FlatBuffersVTableOffset FLATBUFFERS_VTABLE_UNDERLYING_TYPE {
+    VT_A = 4,
+    VT_B = 6,
+    VT_BIG_VECTOR = 8
+  };
+  float a() const {
+    return GetField<float>(VT_A, 0.0f);
+  }
+  bool mutate_a(float _a = 0.0f) {
+    return SetField<float>(VT_A, _a, 0.0f);
+  }
+  const ::flatbuffers::Vector<uint8_t> *b() const {
+    return GetPointer<const ::flatbuffers::Vector<uint8_t> *>(VT_B);
+  }
+  ::flatbuffers::Vector<uint8_t> *mutable_b() {
+    return GetPointer<::flatbuffers::Vector<uint8_t> *>(VT_B);
+  }
+  const ::flatbuffers::Vector64<uint8_t> *big_vector() const {
+    return GetPointer64<const ::flatbuffers::Vector64<uint8_t> *>(VT_BIG_VECTOR);
+  }
+  ::flatbuffers::Vector64<uint8_t> *mutable_big_vector() {
+    return GetPointer64<::flatbuffers::Vector64<uint8_t> *>(VT_BIG_VECTOR);
+  }
+  bool Verify(::flatbuffers::Verifier &verifier) const {
+    return VerifyTableStart(verifier) &&
+           VerifyField<float>(verifier, VT_A, 4) &&
+           VerifyOffset(verifier, VT_B) &&
+           verifier.VerifyVector(b()) &&
+           VerifyOffset64(verifier, VT_BIG_VECTOR) &&
+           verifier.VerifyVector(big_vector()) &&
+           verifier.EndTable();
+  }
+  RootTableT *UnPack(const ::flatbuffers::resolver_function_t *_resolver = nullptr) const;
+  void UnPackTo(RootTableT *_o, const ::flatbuffers::resolver_function_t *_resolver = nullptr) const;
+  static ::flatbuffers::Offset<RootTable> Pack(::flatbuffers::FlatBufferBuilder64 &_fbb, const RootTableT* _o, const ::flatbuffers::rehasher_function_t *_rehasher = nullptr);
+};
+
+struct RootTableBuilder {
+  typedef RootTable Table;
+  ::flatbuffers::FlatBufferBuilder64 &fbb_;
+  ::flatbuffers::uoffset_t start_;
+  void add_a(float a) {
+    fbb_.AddElement<float>(RootTable::VT_A, a, 0.0f);
+  }
+  void add_b(::flatbuffers::Offset<::flatbuffers::Vector<uint8_t>> b) {
+    fbb_.AddOffset(RootTable::VT_B, b);
+  }
+  void add_big_vector(::flatbuffers::Offset64<::flatbuffers::Vector64<uint8_t>> big_vector) {
+    fbb_.AddOffset(RootTable::VT_BIG_VECTOR, big_vector);
+  }
+  explicit RootTableBuilder(::flatbuffers::FlatBufferBuilder64 &_fbb)
+        : fbb_(_fbb) {
+    start_ = fbb_.StartTable();
+  }
+  ::flatbuffers::Offset<RootTable> Finish() {
+    const auto end = fbb_.EndTable(start_);
+    auto o = ::flatbuffers::Offset<RootTable>(end);
+    return o;
+  }
+};
+
+inline ::flatbuffers::Offset<RootTable> CreateRootTable(
+    ::flatbuffers::FlatBufferBuilder64 &_fbb,
+    float a = 0.0f,
+    ::flatbuffers::Offset<::flatbuffers::Vector<uint8_t>> b = 0,
+    ::flatbuffers::Offset64<::flatbuffers::Vector64<uint8_t>> big_vector = 0) {
+  RootTableBuilder builder_(_fbb);
+  builder_.add_big_vector(big_vector);
+  builder_.add_b(b);
+  builder_.add_a(a);
+  return builder_.Finish();
+}
+
+inline ::flatbuffers::Offset<RootTable> CreateRootTableDirect(
+    ::flatbuffers::FlatBufferBuilder64 &_fbb,
+    float a = 0.0f,
+    const std::vector<uint8_t> *b = nullptr,
+    const std::vector<uint8_t> *big_vector = nullptr) {
+  auto big_vector__ = big_vector ? _fbb.CreateVector64(*big_vector) : 0;
+  auto b__ = b ? _fbb.CreateVector<uint8_t>(*b) : 0;
+  return v2::CreateRootTable(
+      _fbb,
+      a,
+      b__,
+      big_vector__);
+}
+
+::flatbuffers::Offset<RootTable> CreateRootTable(::flatbuffers::FlatBufferBuilder64 &_fbb, const RootTableT *_o, const ::flatbuffers::rehasher_function_t *_rehasher = nullptr);
+
+
+inline bool operator==(const RootTableT &lhs, const RootTableT &rhs) {
+  return
+      (lhs.a == rhs.a) &&
+      (lhs.b == rhs.b) &&
+      (lhs.big_vector == rhs.big_vector);
+}
+
+inline bool operator!=(const RootTableT &lhs, const RootTableT &rhs) {
+    return !(lhs == rhs);
+}
+
+
+inline RootTableT *RootTable::UnPack(const ::flatbuffers::resolver_function_t *_resolver) const {
+  auto _o = std::unique_ptr<RootTableT>(new RootTableT());
+  UnPackTo(_o.get(), _resolver);
+  return _o.release();
+}
+
+inline void RootTable::UnPackTo(RootTableT *_o, const ::flatbuffers::resolver_function_t *_resolver) const {
+  (void)_o;
+  (void)_resolver;
+  { auto _e = a(); _o->a = _e; }
+  { auto _e = b(); if (_e) { _o->b.resize(_e->size()); std::copy(_e->begin(), _e->end(), _o->b.begin()); } }
+  { auto _e = big_vector(); if (_e) { _o->big_vector.resize(_e->size()); std::copy(_e->begin(), _e->end(), _o->big_vector.begin()); } }
+}
+
+inline ::flatbuffers::Offset<RootTable> RootTable::Pack(::flatbuffers::FlatBufferBuilder64 &_fbb, const RootTableT* _o, const ::flatbuffers::rehasher_function_t *_rehasher) {
+  return CreateRootTable(_fbb, _o, _rehasher);
+}
+
+inline ::flatbuffers::Offset<RootTable> CreateRootTable(::flatbuffers::FlatBufferBuilder64 &_fbb, const RootTableT *_o, const ::flatbuffers::rehasher_function_t *_rehasher) {
+  (void)_rehasher;
+  (void)_o;
+  struct _VectorArgs { ::flatbuffers::FlatBufferBuilder64 *__fbb; const RootTableT* __o; const ::flatbuffers::rehasher_function_t *__rehasher; } _va = { &_fbb, _o, _rehasher}; (void)_va;
+  auto _a = _o->a;
+  auto _b = _o->b.size() ? _fbb.CreateVector(_o->b) : 0;
+  auto _big_vector = _o->big_vector.size() ? _fbb.CreateVector64(_o->big_vector) : 0;
+  return v2::CreateRootTable(
+      _fbb,
+      _a,
+      _b,
+      _big_vector);
+}
+
+inline const ::flatbuffers::TypeTable *RootTableTypeTable() {
+  static const ::flatbuffers::TypeCode type_codes[] = {
+    { ::flatbuffers::ET_FLOAT, 0, -1 },
+    { ::flatbuffers::ET_UCHAR, 1, -1 },
+    { ::flatbuffers::ET_UCHAR, 1, -1 }
+  };
+  static const char * const names[] = {
+    "a",
+    "b",
+    "big_vector"
+  };
+  static const ::flatbuffers::TypeTable tt = {
+    ::flatbuffers::ST_TABLE, 3, type_codes, nullptr, nullptr, nullptr, names
+  };
+  return &tt;
+}
+
+inline const v2::RootTable *GetRootTable(const void *buf) {
+  return ::flatbuffers::GetRoot<v2::RootTable>(buf);
+}
+
+inline const v2::RootTable *GetSizePrefixedRootTable(const void *buf) {
+  return ::flatbuffers::GetSizePrefixedRoot<v2::RootTable,::flatbuffers::uoffset64_t>(buf);
+}
+
+inline RootTable *GetMutableRootTable(void *buf) {
+  return ::flatbuffers::GetMutableRoot<RootTable>(buf);
+}
+
+inline v2::RootTable *GetMutableSizePrefixedRootTable(void *buf) {
+  return ::flatbuffers::GetMutableSizePrefixedRoot<v2::RootTable,::flatbuffers::uoffset64_t>(buf);
+}
+
+inline bool VerifyRootTableBuffer(
+    ::flatbuffers::Verifier &verifier) {
+  return verifier.VerifyBuffer<v2::RootTable>(nullptr);
+}
+
+inline bool VerifySizePrefixedRootTableBuffer(
+    ::flatbuffers::Verifier &verifier) {
+  return verifier.VerifySizePrefixedBuffer<v2::RootTable,::flatbuffers::uoffset64_t>(nullptr);
+}
+
+inline void FinishRootTableBuffer(
+    ::flatbuffers::FlatBufferBuilder64 &fbb,
+    ::flatbuffers::Offset<v2::RootTable> root) {
+  fbb.Finish(root);
+}
+
+inline void FinishSizePrefixedRootTableBuffer(
+    ::flatbuffers::FlatBufferBuilder64 &fbb,
+    ::flatbuffers::Offset<v2::RootTable> root) {
+  fbb.FinishSizePrefixed(root);
+}
+
+inline std::unique_ptr<v2::RootTableT> UnPackRootTable(
+    const void *buf,
+    const ::flatbuffers::resolver_function_t *res = nullptr) {
+  return std::unique_ptr<v2::RootTableT>(GetRootTable(buf)->UnPack(res));
+}
+
+inline std::unique_ptr<v2::RootTableT> UnPackSizePrefixedRootTable(
+    const void *buf,
+    const ::flatbuffers::resolver_function_t *res = nullptr) {
+  return std::unique_ptr<v2::RootTableT>(GetSizePrefixedRootTable(buf)->UnPack(res));
+}
+
+}  // namespace v2
+
+#endif  // FLATBUFFERS_GENERATED_V2_V2_H_
diff --git a/tests/64bit/offset64_test.cpp b/tests/64bit/offset64_test.cpp
new file mode 100644
index 00000000..8e91fbea
--- /dev/null
+++ b/tests/64bit/offset64_test.cpp
@@ -0,0 +1,447 @@
+#include "offset64_test.h"
+
+#include <stdint.h>
+
+#include <cstdint>
+#include <fstream>
+#include <limits>
+#include <ostream>
+
+#include "evolution/v1_generated.h"
+#include "evolution/v2_generated.h"
+#include "flatbuffers/base.h"
+#include "flatbuffers/buffer.h"
+#include "flatbuffers/flatbuffer_builder.h"
+#include "flatbuffers/flatbuffers.h"
+#include "test_64bit_generated.h"
+#include "test_assert.h"
+
+namespace flatbuffers {
+namespace tests {
+
+void Offset64Test() {
+  FlatBufferBuilder64 builder;
+
+  const size_t far_vector_size = 1LL << 2;
+  const size_t big_vector_size = 1LL << 31;
+
+  {
+    // First create the vectors that will be copied to the buffer.
+    std::vector<uint8_t> far_data;
+    far_data.resize(far_vector_size);
+    far_data[0] = 4;
+    far_data[far_vector_size - 1] = 2;
+
+    std::vector<uint8_t> big_data;
+    big_data.resize(big_vector_size);
+    big_data[0] = 8;
+    big_data[big_vector_size - 1] = 3;
+
+    // Then serialize all the fields that have 64-bit offsets, as these must be
+    // serialized before any 32-bit fields are added to the buffer.
+    const Offset64<Vector<uint8_t>> far_vector_offset =
+        builder.CreateVector64<Vector>(far_data);
+
+    const Offset64<String> far_string_offset =
+        builder.CreateString<Offset64>("some far string");
+
+    const Offset64<Vector64<uint8_t>> big_vector_offset =
+        builder.CreateVector64(big_data);
+
+    // Now that we are done with the 64-bit fields, we can create and add the
+    // normal fields.
+    const Offset<String> near_string_offset =
+        builder.CreateString("some near string");
+
+    // Finish by building the root table by passing in all the offsets.
+    const Offset<RootTable> root_table_offset =
+        CreateRootTable(builder, far_vector_offset, 0, far_string_offset,
+                        big_vector_offset, near_string_offset);
+
+    // Finish the buffer.
+    builder.Finish(root_table_offset);
+
+    // Ensure the buffer is big.
+    TEST_ASSERT(builder.GetSize() > FLATBUFFERS_MAX_BUFFER_SIZE);
+
+    Verifier::Options options;
+    // Allow the verifier to verify 64-bit buffers.
+    options.max_size = FLATBUFFERS_MAX_64_BUFFER_SIZE;
+    options.assert = true;
+
+    Verifier verifier(builder.GetBufferPointer(), builder.GetSize(), options);
+
+    TEST_EQ(VerifyRootTableBuffer(verifier), true);
+  }
+
+  {
+    const RootTable *root_table = GetRootTable(builder.GetBufferPointer());
+
+    // Expect the far vector to be properly sized.
+    TEST_EQ(root_table->far_vector()->size(), far_vector_size);
+    TEST_EQ(root_table->far_vector()->Get(0), 4);
+    TEST_EQ(root_table->far_vector()->Get(far_vector_size - 1), 2);
+
+    TEST_EQ_STR(root_table->far_string()->c_str(), "some far string");
+
+    // Expect the big vector to be properly sized.
+    TEST_EQ(root_table->big_vector()->size(), big_vector_size);
+    TEST_EQ(root_table->big_vector()->Get(0), 8);
+    TEST_EQ(root_table->big_vector()->Get(big_vector_size - 1), 3);
+
+    TEST_EQ_STR(root_table->near_string()->c_str(), "some near string");
+  }
+}
+
+void Offset64SerializedFirst() {
+  FlatBufferBuilder64 fbb;
+
+  // First create the vectors that will be copied to the buffer.
+  std::vector<uint8_t> data;
+  data.resize(64);
+
+  // Then serialize all the fields that have 64-bit offsets, as these must be
+  // serialized before any 32-bit fields are added to the buffer.
+  fbb.CreateVector64(data);
+
+  // TODO(derekbailey): figure out how to test assertions.
+  // Uncommenting this line should fail the test with an assertion.
+  // fbb.CreateString("some near string");
+
+  fbb.CreateVector64(data);
+}
+
+void Offset64NestedFlatBuffer() {
+  FlatBufferBuilder64 fbb;
+
+  // First serialize a nested buffer.
+  const Offset<String> near_string_offset =
+      fbb.CreateString("nested: some near string");
+
+  // Finish by building the root table by passing in all the offsets.
+  const Offset<RootTable> root_table_offset =
+      CreateRootTable(fbb, 0, 0, 0, 0, near_string_offset, 0);
+
+  // Finish the buffer.
+  fbb.Finish(root_table_offset);
+
+  // Ensure the buffer is valid.
+  const RootTable *root_table = GetRootTable(fbb.GetBufferPointer());
+  TEST_EQ_STR(root_table->near_string()->c_str(), "nested: some near string");
+
+  // Copy the data out of the builder.
+  std::vector<uint8_t> nested_data{ fbb.GetBufferPointer(),
+                                    fbb.GetBufferPointer() + fbb.GetSize() };
+
+  {
+    // Clear so we can reuse the builder.
+    fbb.Clear();
+
+    const Offset64<Vector64<uint8_t>> nested_flatbuffer_offset =
+        fbb.CreateVector64<Vector64>(nested_data);
+
+    // Now that we are done with the 64-bit fields, we can create and add the
+    // normal fields.
+    const Offset<String> near_string_offset =
+        fbb.CreateString("some near string");
+
+    // Finish by building the root table by passing in all the offsets.
+    const Offset<RootTable> root_table_offset = CreateRootTable(
+        fbb, 0, 0, 0, 0, near_string_offset, nested_flatbuffer_offset);
+
+    // Finish the buffer.
+    fbb.Finish(root_table_offset);
+
+    Verifier::Options options;
+    // Allow the verifier to verify 64-bit buffers.
+    options.max_size = FLATBUFFERS_MAX_64_BUFFER_SIZE;
+    options.assert = true;
+
+    Verifier verifier(fbb.GetBufferPointer(), fbb.GetSize(), options);
+
+    TEST_EQ(VerifyRootTableBuffer(verifier), true);
+  }
+
+  {
+    const RootTable *root_table = GetRootTable(fbb.GetBufferPointer());
+
+    // Test that the parent buffer field is ok.
+    TEST_EQ_STR(root_table->near_string()->c_str(), "some near string");
+
+    // Expect nested buffer to be properly sized.
+    TEST_EQ(root_table->nested_root()->size(), nested_data.size());
+
+    // Expect the direct accessors to the nested buffer work.
+    TEST_EQ_STR(root_table->nested_root_nested_root()->near_string()->c_str(),
+                "nested: some near string");
+  }
+}
+
+void Offset64CreateDirect() {
+  FlatBufferBuilder64 fbb;
+
+  // Create a vector of some data
+  std::vector<uint8_t> data{ 0, 1, 2 };
+
+  // Call the "Direct" creation method to ensure that things are added to the
+  // buffer in the correct order, Offset64 first followed by any Offsets.
+  const Offset<RootTable> root_table_offset = CreateRootTableDirect(
+      fbb, &data, 0, "some far string", &data, "some near string");
+
+  // Finish the buffer.
+  fbb.Finish(root_table_offset);
+
+  Verifier::Options options;
+  // Allow the verifier to verify 64-bit buffers.
+  options.max_size = FLATBUFFERS_MAX_64_BUFFER_SIZE;
+  options.assert = true;
+
+  Verifier verifier(fbb.GetBufferPointer(), fbb.GetSize(), options);
+
+  TEST_EQ(VerifyRootTableBuffer(verifier), true);
+
+  // Verify the data.
+  const RootTable *root_table = GetRootTable(fbb.GetBufferPointer());
+  TEST_EQ(root_table->far_vector()->size(), data.size());
+  TEST_EQ(root_table->big_vector()->size(), data.size());
+  TEST_EQ_STR(root_table->far_string()->c_str(), "some far string");
+  TEST_EQ_STR(root_table->near_string()->c_str(), "some near string");
+}
+
+void Offset64Evolution() {
+  // Some common data for the tests.
+  const std::vector<uint8_t> data = { 1, 2, 3, 4 };
+  const std::vector<uint8_t> big_data = { 6, 7, 8, 9, 10 };
+
+  // Built V1 read V2
+  {
+    // Use the 32-bit builder since V1 doesn't have any 64-bit offsets.
+    FlatBufferBuilder builder;
+
+    builder.Finish(v1::CreateRootTableDirect(builder, 1234, &data));
+
+    // Use each version to get a view at the root table.
+    auto v1_root = v1::GetRootTable(builder.GetBufferPointer());
+    auto v2_root = v2::GetRootTable(builder.GetBufferPointer());
+
+    // Test field equivalents for fields common to V1 and V2.
+    TEST_EQ(v1_root->a(), v2_root->a());
+
+    TEST_EQ(v1_root->b(), v2_root->b());
+    TEST_EQ(v1_root->b()->Get(2), 3);
+    TEST_EQ(v2_root->b()->Get(2), 3);
+
+    // This field is added in V2, so it should be null since V1 couldn't have
+    // written it.
+    TEST_ASSERT(v2_root->big_vector() == nullptr);
+  }
+
+  // Built V2 read V1
+  {
+    // Use the 64-bit builder since V2 has 64-bit offsets.
+    FlatBufferBuilder64 builder;
+
+    builder.Finish(v2::CreateRootTableDirect(builder, 1234, &data, &big_data));
+
+    // Use each version to get a view at the root table.
+    auto v1_root = v1::GetRootTable(builder.GetBufferPointer());
+    auto v2_root = v2::GetRootTable(builder.GetBufferPointer());
+
+    // Test field equivalents for fields common to V1 and V2.
+    TEST_EQ(v1_root->a(), v2_root->a());
+
+    TEST_EQ(v1_root->b(), v2_root->b());
+    TEST_EQ(v1_root->b()->Get(2), 3);
+    TEST_EQ(v2_root->b()->Get(2), 3);
+
+    // Test that V2 can read the big vector, which V1 doesn't even have
+    // accessors for (i.e. v1_root->big_vector() doesn't exist).
+    TEST_ASSERT(v2_root->big_vector() != nullptr);
+    TEST_EQ(v2_root->big_vector()->size(), big_data.size());
+    TEST_EQ(v2_root->big_vector()->Get(2), 8);
+  }
+
+  // Built V2 read V1, bigger than max 32-bit buffer sized.
+  // This checks that even a large buffer can still be read by V1.
+  {
+    // Use the 64-bit builder since V2 has 64-bit offsets.
+    FlatBufferBuilder64 builder;
+
+    std::vector<uint8_t> giant_data;
+    giant_data.resize(1LL << 31);
+    giant_data[2] = 42;
+
+    builder.Finish(
+        v2::CreateRootTableDirect(builder, 1234, &data, &giant_data));
+
+    // Ensure the buffer is bigger than the 32-bit size limit for V1.
+    TEST_ASSERT(builder.GetSize() > FLATBUFFERS_MAX_BUFFER_SIZE);
+
+    // Use each version to get a view at the root table.
+    auto v1_root = v1::GetRootTable(builder.GetBufferPointer());
+    auto v2_root = v2::GetRootTable(builder.GetBufferPointer());
+
+    // Test field equivalents for fields common to V1 and V2.
+    TEST_EQ(v1_root->a(), v2_root->a());
+
+    TEST_EQ(v1_root->b(), v2_root->b());
+    TEST_EQ(v1_root->b()->Get(2), 3);
+    TEST_EQ(v2_root->b()->Get(2), 3);
+
+    // Test that V2 can read the big vector, which V1 doesn't even have
+    // accessors for (i.e. v1_root->big_vector() doesn't exist).
+    TEST_ASSERT(v2_root->big_vector() != nullptr);
+    TEST_EQ(v2_root->big_vector()->size(), giant_data.size());
+    TEST_EQ(v2_root->big_vector()->Get(2), 42);
+  }
+}
+
+void Offset64VectorOfStructs() {
+  FlatBufferBuilder64 builder;
+
+  std::vector<LeafStruct> far_leaves;
+  far_leaves.emplace_back(LeafStruct{ 123, 4.567 });
+  far_leaves.emplace_back(LeafStruct{ 987, 6.543 });
+
+  std::vector<LeafStruct> big_leaves;
+  big_leaves.emplace_back(LeafStruct{ 72, 72.8 });
+  big_leaves.emplace_back(LeafStruct{ 82, 82.8 });
+  big_leaves.emplace_back(LeafStruct{ 92, 92.8 });
+
+  // Add the two vectors of leaf structs.
+  const Offset<RootTable> root_table_offset =
+      CreateRootTableDirect(builder, nullptr, 0, nullptr, nullptr, nullptr,
+                            nullptr, &far_leaves, &big_leaves);
+
+  // Finish the buffer.
+  builder.Finish(root_table_offset);
+
+  Verifier::Options options;
+  // Allow the verifier to verify 64-bit buffers.
+  options.max_size = FLATBUFFERS_MAX_64_BUFFER_SIZE;
+  options.assert = true;
+
+  Verifier verifier(builder.GetBufferPointer(), builder.GetSize(), options);
+
+  TEST_EQ(VerifyRootTableBuffer(verifier), true);
+
+  // Verify the data.
+  const RootTable *root_table = GetRootTable(builder.GetBufferPointer());
+  TEST_EQ(root_table->far_struct_vector()->size(), far_leaves.size());
+  TEST_EQ(root_table->far_struct_vector()->Get(0)->a(), 123);
+  TEST_EQ(root_table->far_struct_vector()->Get(0)->b(), 4.567);
+  TEST_EQ(root_table->far_struct_vector()->Get(1)->a(), 987);
+  TEST_EQ(root_table->far_struct_vector()->Get(1)->b(), 6.543);
+
+  TEST_EQ(root_table->big_struct_vector()->size(), big_leaves.size());
+  TEST_EQ(root_table->big_struct_vector()->Get(0)->a(), 72);
+  TEST_EQ(root_table->big_struct_vector()->Get(0)->b(), 72.8);
+  TEST_EQ(root_table->big_struct_vector()->Get(1)->a(), 82);
+  TEST_EQ(root_table->big_struct_vector()->Get(1)->b(), 82.8);
+  TEST_EQ(root_table->big_struct_vector()->Get(2)->a(), 92);
+  TEST_EQ(root_table->big_struct_vector()->Get(2)->b(), 92.8);
+}
+
+void Offset64SizePrefix() {
+  FlatBufferBuilder64 builder;
+
+  // First serialize a nested buffer.
+  const Offset<String> near_string_offset =
+      builder.CreateString("some near string");
+
+  // Finish by building the root table by passing in all the offsets.
+  const Offset<RootTable> root_table_offset =
+      CreateRootTable(builder, 0, 0, 0, 0, near_string_offset, 0);
+
+  // Finish the buffer.
+  FinishSizePrefixedRootTableBuffer(builder, root_table_offset);
+
+  TEST_EQ(GetPrefixedSize<uoffset64_t>(builder.GetBufferPointer()),
+          builder.GetSize() - sizeof(uoffset64_t));
+
+  Verifier::Options options;
+  // Allow the verifier to verify 64-bit buffers.
+  options.max_size = FLATBUFFERS_MAX_64_BUFFER_SIZE;
+  options.assert = true;
+
+  Verifier verifier(builder.GetBufferPointer(), builder.GetSize(), options);
+
+  TEST_EQ(VerifySizePrefixedRootTableBuffer(verifier), true);
+
+  const RootTable *root_table =
+      GetSizePrefixedRootTable(builder.GetBufferPointer());
+
+  // Verify the fields.
+  TEST_EQ_STR(root_table->near_string()->c_str(), "some near string");
+}
+
+void Offset64ManyVectors() {
+  FlatBufferBuilder64 builder;
+
+  // Setup some data to serialize.
+  std::vector<int8_t> data;
+  data.resize(20);
+  data.front() = 42;
+  data.back() = 18;
+
+  const size_t kNumVectors = 20;
+
+  // First serialize all the 64-bit address vectors. We need to store all the
+  // offsets to later add to a wrapper table. We cannot serialize one vector and
+  // then add it to a table immediately, as it would violate the strict ordering
+  // of putting all 64-bit things at the tail of the buffer.
+  std::array<Offset64<Vector<int8_t>>, kNumVectors> offsets_64bit;
+  for (size_t i = 0; i < kNumVectors; ++i) {
+    offsets_64bit[i] = builder.CreateVector64<Vector>(data);
+  }
+
+  // Create some unrelated, 64-bit offset value for later testing.
+  const Offset64<String> far_string_offset =
+      builder.CreateString<Offset64>("some far string");
+
+  // Now place all the offsets into their own wrapper tables. Again, we have to
+  // store the offsets before we can add them to the root table vector.
+  std::array<Offset<WrapperTable>, kNumVectors> offsets_wrapper;
+  for (size_t i = 0; i < kNumVectors; ++i) {
+    offsets_wrapper[i] = CreateWrapperTable(builder, offsets_64bit[i]);
+  }
+
+  // Now create the 32-bit vector that is stored in the root table.
+  // TODO(derekbailey): the array type wasn't auto deduced, see if that could be
+  // fixed.
+  const Offset<Vector<Offset<WrapperTable>>> many_vectors_offset =
+      builder.CreateVector<Offset<WrapperTable>>(offsets_wrapper);
+
+  // Finish by building using the root table builder, to exercise a different
+  // code path than the other tests.
+  RootTableBuilder root_table_builder(builder);
+  root_table_builder.add_many_vectors(many_vectors_offset);
+  root_table_builder.add_far_string(far_string_offset);
+  const Offset<RootTable> root_table_offset = root_table_builder.Finish();
+
+  // Finish the buffer.
+  FinishRootTableBuffer(builder, root_table_offset);
+
+  Verifier::Options options;
+  // Allow the verifier to verify 64-bit buffers.
+  options.max_size = FLATBUFFERS_MAX_64_BUFFER_SIZE;
+  options.assert = true;
+
+  Verifier verifier(builder.GetBufferPointer(), builder.GetSize(), options);
+
+  TEST_EQ(VerifyRootTableBuffer(verifier), true);
+
+  const RootTable *root_table = GetRootTable(builder.GetBufferPointer());
+
+  // Verify the fields.
+  TEST_EQ_STR(root_table->far_string()->c_str(), "some far string");
+  TEST_EQ(root_table->many_vectors()->size(), kNumVectors);
+
+  // Spot check one of the vectors.
+  TEST_EQ(root_table->many_vectors()->Get(12)->vector()->size(), 20);
+  TEST_EQ(root_table->many_vectors()->Get(12)->vector()->Get(0), 42);
+  TEST_EQ(root_table->many_vectors()->Get(12)->vector()->Get(19), 18);
+}
+
+}  // namespace tests
+}  // namespace flatbuffers
diff --git a/tests/64bit/offset64_test.h b/tests/64bit/offset64_test.h
new file mode 100644
index 00000000..8dacee1f
--- /dev/null
+++ b/tests/64bit/offset64_test.h
@@ -0,0 +1,19 @@
+#ifndef TESTS_64BIT_OFFSET64_TEST_H
+#define TESTS_64BIT_OFFSET64_TEST_H
+
+namespace flatbuffers {
+namespace tests {
+
+void Offset64Test();
+void Offset64SerializedFirst();
+void Offset64NestedFlatBuffer();
+void Offset64CreateDirect();
+void Offset64Evolution();
+void Offset64VectorOfStructs();
+void Offset64SizePrefix();
+void Offset64ManyVectors();
+
+}  // namespace tests
+}  // namespace flatbuffers
+
+#endif // TESTS_64BIT_OFFSET64_TEST_H
diff --git a/tests/64bit/test_64bit.afb b/tests/64bit/test_64bit.afb
new file mode 100644
index 00000000..f6cef00e
--- /dev/null
+++ b/tests/64bit/test_64bit.afb
@@ -0,0 +1,74 @@
+// Annotated Flatbuffer Binary
+//
+// Schema file: tests/64bit/test_64bit.fbs
+// Binary file: tests/64bit/test_64bit.bin
+
+header:
+  +0x00 | 1C 00 00 00             | UOffset32  | 0x0000001C (28) Loc: 0x1C          | offset to root table `RootTable`
+
+padding:
+  +0x04 | 00 00 00 00             | uint8_t[4] | ....                               | padding
+
+vtable (RootTable):
+  +0x08 | 14 00                   | uint16_t   | 0x0014 (20)                        | size of this vtable
+  +0x0A | 34 00                   | uint16_t   | 0x0034 (52)                        | size of referring table
+  +0x0C | 04 00                   | VOffset16  | 0x0004 (4)                         | offset to field `far_vector` (id: 0)
+  +0x0E | 10 00                   | VOffset16  | 0x0010 (16)                        | offset to field `a` (id: 1)
+  +0x10 | 14 00                   | VOffset16  | 0x0014 (20)                        | offset to field `far_string` (id: 2)
+  +0x12 | 24 00                   | VOffset16  | 0x0024 (36)                        | offset to field `big_vector` (id: 3)
+  +0x14 | 20 00                   | VOffset16  | 0x0020 (32)                        | offset to field `near_string` (id: 4)
+  +0x16 | 00 00                   | VOffset16  | 0x0000 (0)                         | offset to field `nested_root` (id: 5) <null> (Vector64)
+  +0x18 | 00 00                   | VOffset16  | 0x0000 (0)                         | offset to field `far_struct_vector` (id: 6) <null> (Vector)
+  +0x1A | 2C 00                   | VOffset16  | 0x002C (44)                        | offset to field `big_struct_vector` (id: 7)
+
+root_table (RootTable):
+  +0x1C | 14 00 00 00             | SOffset32  | 0x00000014 (20) Loc: 0x08          | offset to vtable
+  +0x20 | D0 00 00 00 00 00 00 00 | UOffset64  | 0x00000000000000D0 (208) Loc: 0xF0 | offset to field `far_vector` (vector)
+  +0x28 | 00 00 00 00             | uint8_t[4] | ....                               | padding
+  +0x2C | D2 04 00 00             | uint32_t   | 0x000004D2 (1234)                  | table field `a` (Int)
+  +0x30 | 8C 00 00 00 00 00 00 00 | UOffset64  | 0x000000000000008C (140) Loc: 0xBC | offset to field `far_string` (string)
+  +0x38 | 00 00 00 00             | uint8_t[4] | ....                               | padding
+  +0x3C | 40 00 00 00             | UOffset32  | 0x00000040 (64) Loc: 0x7C          | offset to field `near_string` (string)
+  +0x40 | 70 00 00 00 00 00 00 00 | UOffset64  | 0x0000000000000070 (112) Loc: 0xB0 | offset to field `big_vector` (vector64)
+  +0x48 | 08 00 00 00 00 00 00 00 | UOffset64  | 0x0000000000000008 (8) Loc: 0x50   | offset to field `big_struct_vector` (vector64)
+
+vector64 (RootTable.big_struct_vector):
+  +0x50 | 02 00 00 00 00 00 00 00 | uint64_t   | 0x0000000000000002 (2)             | length of vector (# items)
+  +0x58 | 0C 00 00 00             | uint32_t   | 0x0000000C (12)                    | struct field `[0].a` of 'LeafStruct' (Int)
+  <4 regions omitted>
+  +0x70 | 33 33 33 33 33 33 22 40 | double     | 0x4022333333333333 (9.1)           | struct field `[1].b` of 'LeafStruct' (Double)
+
+padding:
+  +0x78 | 00 00 00 00             | uint8_t[4] | ....                               | padding
+
+string (RootTable.near_string):
+  +0x7C | 2F 00 00 00             | uint32_t   | 0x0000002F (47)                    | length of string
+  +0x80 | 74 68 69 73 20 69 73 20 | char[47]   | this is                            | string literal
+  +0x88 | 61 20 6E 65 61 72 20 73 |            | a near s
+  +0x90 | 74 72 69 6E 67 20 77 68 |            | tring wh
+  +0x98 | 69 63 68 20 68 61 73 20 |            | ich has 
+  +0xA0 | 61 20 33 32 2D 62 69 74 |            | a 32-bit
+  +0xA8 | 20 6F 66 66 73 65 74    |            |  offset
+  +0xAF | 00                      | char       | 0x00 (0)                           | string terminator
+
+vector64 (RootTable.big_vector):
+  +0xB0 | 04 00 00 00 00 00 00 00 | uint64_t   | 0x0000000000000004 (4)             | length of vector (# items)
+  +0xB8 | 05                      | uint8_t    | 0x05 (5)                           | value[0]
+  <2 regions omitted>
+  +0xBB | 08                      | uint8_t    | 0x08 (8)                           | value[3]
+
+string (RootTable.far_string):
+  +0xBC | 2E 00 00 00             | uint32_t   | 0x0000002E (46)                    | length of string
+  +0xC0 | 74 68 69 73 20 69 73 20 | char[46]   | this is                            | string literal
+  +0xC8 | 61 20 66 61 72 20 73 74 |            | a far st
+  +0xD0 | 72 69 6E 67 20 77 68 69 |            | ring whi
+  +0xD8 | 63 68 20 68 61 73 20 61 |            | ch has a
+  +0xE0 | 20 36 34 2D 62 69 74 20 |            |  64-bit 
+  +0xE8 | 6F 66 66 73 65 74       |            | offset
+  +0xEE | 00                      | char       | 0x00 (0)                           | string terminator
+
+vector (RootTable.far_vector):
+  +0xF0 | 03 00 00 00             | uint32_t   | 0x00000003 (3)                     | length of vector (# items)
+  +0xF4 | 01                      | uint8_t    | 0x01 (1)                           | value[0]
+  +0xF5 | 02                      | uint8_t    | 0x02 (2)                           | value[1]
+  +0xF6 | 03                      | uint8_t    | 0x03 (3)                           | value[2]
diff --git a/tests/64bit/test_64bit.bfbs b/tests/64bit/test_64bit.bfbs
new file mode 100644
index 00000000..29360deb
--- /dev/null
+++ b/tests/64bit/test_64bit.bfbs
diff --git a/tests/64bit/test_64bit.bin b/tests/64bit/test_64bit.bin
new file mode 100644
index 00000000..a8d2d2e1
--- /dev/null
+++ b/tests/64bit/test_64bit.bin
diff --git a/tests/64bit/test_64bit.fbs b/tests/64bit/test_64bit.fbs
new file mode 100644
index 00000000..6bc787e9
--- /dev/null
+++ b/tests/64bit/test_64bit.fbs
@@ -0,0 +1,49 @@
+struct LeafStruct {
+  a:int;
+  b:double;
+}
+
+table WrapperTable {
+  // A normal 32-bit sized vector that could be very far away (64-bit address).
+  vector:[int8] (offset64);
+}
+
+table RootTable {
+  // A normal 32-bit sized vector, that could be very far away (64-bit address).
+  far_vector:[ubyte] (offset64);
+
+  // An inplace value just to check that vtable offsets are correct.
+  a:int;
+
+  // A normal 32-bit sized string, that could be very far away (64-bit address).
+  far_string:string (offset64);
+
+  // A big 64-bit sized vector, that could be very far away (64-bit address).
+  big_vector:[ubyte] (vector64);
+
+  // A normal 32-bit sized string that is no far away (32-bit address).
+  near_string:string;
+
+  // A big 64-bit sized vector that is a nested flatbuffers (64-bit address).
+  nested_root:[ubyte] (vector64, nested_flatbuffer: "RootTable");
+
+  // A normal 32-bit size vector of structs, that could be very far away 
+  // (64-bit address)
+  far_struct_vector:[LeafStruct] (offset64);
+
+  // A big 64-bit size vector of structs that could be very far away 
+  // (64-bit address)
+  big_struct_vector:[LeafStruct] (vector64);
+
+  // A normal 32-bit size vector of tables. Currently 64-bit vectors don't 
+  // support tables as it would require serializing a table (32-bit) before the
+  // vector (64-bit), which is not allowed.
+  //
+  // This demonstrates how you could have many vectors in the buffer, by 
+  // effectively having a vector of 64-bit vectors. The IDL doesn't support
+  // nested vecotrs (e.g.: [[type]] ), so going through a wrapper table allows
+  // this.
+  many_vectors:[WrapperTable];
+}
+
+root_type RootTable; 
diff --git a/tests/64bit/test_64bit.json b/tests/64bit/test_64bit.json
new file mode 100644
index 00000000..4b24f4e7
--- /dev/null
+++ b/tests/64bit/test_64bit.json
@@ -0,0 +1,17 @@
+{
+  "far_vector": [1, 2, 3],
+  "a": 1234,
+  "far_string": "this is a far string which has a 64-bit offset",
+  "big_vector": [5, 6, 7, 8],
+  "near_string": "this is a near string which has a 32-bit offset",
+  "big_struct_vector": [
+    {
+      "a": 12,
+      "b": 3.456
+    },
+    { 
+      "a": 78,
+      "b": 9.10
+    }
+  ]
+}
diff --git a/tests/64bit/test_64bit_bfbs_generated.h b/tests/64bit/test_64bit_bfbs_generated.h
new file mode 100644
index 00000000..ca017e78
--- /dev/null
+++ b/tests/64bit/test_64bit_bfbs_generated.h
@@ -0,0 +1,93 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+
+#ifndef FLATBUFFERS_GENERATED_TEST64BIT_BFBS_H_
+#define FLATBUFFERS_GENERATED_TEST64BIT_BFBS_H_
+
+#include "flatbuffers/flatbuffers.h"
+
+// Ensure the included flatbuffers.h is the same version as when this file was
+// generated, otherwise it may not be compatible.
+static_assert(FLATBUFFERS_VERSION_MAJOR == 23 &&
+              FLATBUFFERS_VERSION_MINOR == 5 &&
+              FLATBUFFERS_VERSION_REVISION == 8,
+             "Non-compatible flatbuffers version included");
+
+struct RootTableBinarySchema {
+  static const uint8_t *data() {
+    // Buffer containing the binary schema.
+    static const uint8_t bfbsData[1180] = {
+      0x1C,0x00,0x00,0x00,0x42,0x46,0x42,0x53,0x14,0x00,0x20,0x00,0x04,0x00,0x08,0x00,0x0C,0x00,0x10,0x00,
+      0x14,0x00,0x18,0x00,0x00,0x00,0x1C,0x00,0x14,0x00,0x00,0x00,0x34,0x00,0x00,0x00,0x2C,0x00,0x00,0x00,
+      0x20,0x00,0x00,0x00,0x14,0x00,0x00,0x00,0x54,0x00,0x00,0x00,0x08,0x00,0x00,0x00,0x2C,0x00,0x00,0x00,
+      0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+      0x00,0x00,0x00,0x00,0x03,0x00,0x00,0x00,0x60,0x03,0x00,0x00,0x28,0x00,0x00,0x00,0xBC,0x02,0x00,0x00,
+      0x01,0x00,0x00,0x00,0x0C,0x00,0x00,0x00,0x08,0x00,0x0C,0x00,0x04,0x00,0x08,0x00,0x08,0x00,0x00,0x00,
+      0x5C,0x03,0x00,0x00,0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7C,0xFD,0xFF,0xFF,0x38,0x00,0x00,0x00,
+      0x0C,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x40,0x03,0x00,0x00,0x09,0x00,0x00,0x00,0x1C,0x02,0x00,0x00,
+      0x68,0x00,0x00,0x00,0x80,0x01,0x00,0x00,0xE0,0x01,0x00,0x00,0xAC,0x00,0x00,0x00,0x2C,0x02,0x00,0x00,
+      0x1C,0x00,0x00,0x00,0x3C,0x01,0x00,0x00,0xE8,0x00,0x00,0x00,0x09,0x00,0x00,0x00,0x52,0x6F,0x6F,0x74,
+      0x54,0x61,0x62,0x6C,0x65,0x00,0x00,0x00,0xF8,0xFE,0xFF,0xFF,0x00,0x00,0x00,0x01,0x08,0x00,0x14,0x00,
+      0x18,0x00,0x00,0x00,0x04,0x00,0x00,0x00,0x78,0xFF,0xFF,0xFF,0x00,0x00,0x0E,0x0F,0x02,0x00,0x00,0x00,
+      0x04,0x00,0x00,0x00,0x0C,0x00,0x00,0x00,0x6D,0x61,0x6E,0x79,0x5F,0x76,0x65,0x63,0x74,0x6F,0x72,0x73,
+      0x00,0x00,0x00,0x00,0xA0,0xFE,0xFF,0xFF,0x00,0x00,0x01,0x01,0x07,0x00,0x12,0x00,0x2C,0x00,0x00,0x00,
+      0x14,0x00,0x00,0x00,0x10,0x00,0x14,0x00,0x06,0x00,0x07,0x00,0x08,0x00,0x00,0x00,0x0C,0x00,0x10,0x00,
+      0x10,0x00,0x00,0x00,0x00,0x00,0x12,0x0F,0x00,0x00,0x00,0x00,0x08,0x00,0x00,0x00,0x04,0x00,0x00,0x00,
+      0x11,0x00,0x00,0x00,0x62,0x69,0x67,0x5F,0x73,0x74,0x72,0x75,0x63,0x74,0x5F,0x76,0x65,0x63,0x74,0x6F,
+      0x72,0x00,0x00,0x00,0xF0,0xFE,0xFF,0xFF,0x00,0x00,0x01,0x01,0x06,0x00,0x10,0x00,0x28,0x00,0x00,0x00,
+      0x14,0x00,0x00,0x00,0x10,0x00,0x10,0x00,0x06,0x00,0x07,0x00,0x08,0x00,0x00,0x00,0x00,0x00,0x0C,0x00,
+      0x10,0x00,0x00,0x00,0x00,0x00,0x0E,0x0F,0x00,0x00,0x00,0x00,0x10,0x00,0x00,0x00,0x11,0x00,0x00,0x00,
+      0x66,0x61,0x72,0x5F,0x73,0x74,0x72,0x75,0x63,0x74,0x5F,0x76,0x65,0x63,0x74,0x6F,0x72,0x00,0x00,0x00,
+      0x3C,0xFF,0xFF,0xFF,0x00,0x00,0x01,0x01,0x05,0x00,0x0E,0x00,0x18,0x00,0x00,0x00,0x04,0x00,0x00,0x00,
+      0x80,0xFF,0xFF,0xFF,0x00,0x00,0x12,0x04,0x08,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x0B,0x00,0x00,0x00,
+      0x6E,0x65,0x73,0x74,0x65,0x64,0x5F,0x72,0x6F,0x6F,0x74,0x00,0x1C,0x00,0x14,0x00,0x0C,0x00,0x10,0x00,
+      0x08,0x00,0x0A,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x07,0x00,
+      0x1C,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x04,0x00,0x0C,0x00,0x14,0x00,0x00,0x00,0x04,0x00,0x00,0x00,
+      0x90,0xFD,0xFF,0xFF,0x00,0x00,0x00,0x0D,0x01,0x00,0x00,0x00,0x0B,0x00,0x00,0x00,0x6E,0x65,0x61,0x72,
+      0x5F,0x73,0x74,0x72,0x69,0x6E,0x67,0x00,0xBC,0xFF,0xFF,0xFF,0x00,0x00,0x01,0x01,0x03,0x00,0x0A,0x00,
+      0x28,0x00,0x00,0x00,0x14,0x00,0x00,0x00,0x10,0x00,0x10,0x00,0x06,0x00,0x07,0x00,0x00,0x00,0x00,0x00,
+      0x08,0x00,0x0C,0x00,0x10,0x00,0x00,0x00,0x00,0x00,0x12,0x04,0x08,0x00,0x00,0x00,0x01,0x00,0x00,0x00,
+      0x0A,0x00,0x00,0x00,0x62,0x69,0x67,0x5F,0x76,0x65,0x63,0x74,0x6F,0x72,0x00,0x00,0x20,0x00,0x14,0x00,
+      0x0C,0x00,0x10,0x00,0x08,0x00,0x0A,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+      0x00,0x00,0x06,0x00,0x00,0x00,0x07,0x00,0x20,0x00,0x00,0x00,0x00,0x00,0x01,0x01,0x02,0x00,0x08,0x00,
+      0x14,0x00,0x00,0x00,0x04,0x00,0x00,0x00,0x24,0xFE,0xFF,0xFF,0x00,0x00,0x00,0x0D,0x01,0x00,0x00,0x00,
+      0x0A,0x00,0x00,0x00,0x66,0x61,0x72,0x5F,0x73,0x74,0x72,0x69,0x6E,0x67,0x00,0x00,0xB0,0xFE,0xFF,0xFF,
+      0x01,0x00,0x06,0x00,0x14,0x00,0x00,0x00,0x04,0x00,0x00,0x00,0x50,0xFE,0xFF,0xFF,0x00,0x00,0x00,0x07,
+      0x01,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x61,0x00,0x00,0x00,0x90,0xFF,0xFF,0xFF,0x01,0x01,0x04,0x00,
+      0x14,0x00,0x00,0x00,0x04,0x00,0x00,0x00,0x70,0xFF,0xFF,0xFF,0x00,0x00,0x0E,0x04,0x01,0x00,0x00,0x00,
+      0x0A,0x00,0x00,0x00,0x66,0x61,0x72,0x5F,0x76,0x65,0x63,0x74,0x6F,0x72,0x00,0x00,0x14,0x00,0x14,0x00,
+      0x04,0x00,0x08,0x00,0x00,0x00,0x0C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x10,0x00,0x14,0x00,0x00,0x00,
+      0x18,0x00,0x00,0x00,0x0C,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0xA8,0x00,0x00,0x00,0x01,0x00,0x00,0x00,
+      0x38,0x00,0x00,0x00,0x0C,0x00,0x00,0x00,0x57,0x72,0x61,0x70,0x70,0x65,0x72,0x54,0x61,0x62,0x6C,0x65,
+      0x00,0x00,0x00,0x00,0x20,0x00,0x10,0x00,0x08,0x00,0x0C,0x00,0x00,0x00,0x06,0x00,0x00,0x00,0x00,0x00,
+      0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x04,0x00,0x00,0x00,0x05,0x00,0x20,0x00,0x00,0x00,
+      0x01,0x01,0x04,0x00,0x24,0x00,0x00,0x00,0x14,0x00,0x00,0x00,0x10,0x00,0x0C,0x00,0x06,0x00,0x07,0x00,
+      0x00,0x00,0x00,0x00,0x00,0x00,0x08,0x00,0x10,0x00,0x00,0x00,0x00,0x00,0x0E,0x03,0x01,0x00,0x00,0x00,
+      0x06,0x00,0x00,0x00,0x76,0x65,0x63,0x74,0x6F,0x72,0x00,0x00,0x14,0x00,0x1C,0x00,0x08,0x00,0x0C,0x00,
+      0x07,0x00,0x10,0x00,0x14,0x00,0x00,0x00,0x00,0x00,0x18,0x00,0x14,0x00,0x00,0x00,0x00,0x00,0x00,0x01,
+      0x38,0x00,0x00,0x00,0x28,0x00,0x00,0x00,0x08,0x00,0x00,0x00,0x10,0x00,0x00,0x00,0x04,0x00,0x00,0x00,
+      0x10,0x00,0x00,0x00,0x2F,0x2F,0x74,0x65,0x73,0x74,0x5F,0x36,0x34,0x62,0x69,0x74,0x2E,0x66,0x62,0x73,
+      0x00,0x00,0x00,0x00,0x02,0x00,0x00,0x00,0x78,0x00,0x00,0x00,0x20,0x00,0x00,0x00,0x0A,0x00,0x00,0x00,
+      0x4C,0x65,0x61,0x66,0x53,0x74,0x72,0x75,0x63,0x74,0x00,0x00,0x0C,0x00,0x10,0x00,0x08,0x00,0x0C,0x00,
+      0x04,0x00,0x06,0x00,0x0C,0x00,0x00,0x00,0x01,0x00,0x08,0x00,0x28,0x00,0x00,0x00,0x14,0x00,0x00,0x00,
+      0x10,0x00,0x10,0x00,0x07,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x08,0x00,0x0C,0x00,0x10,0x00,0x00,0x00,
+      0x00,0x00,0x00,0x0C,0x08,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x62,0x00,0x1E,0x00,
+      0x10,0x00,0x08,0x00,0x0C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+      0x00,0x00,0x00,0x00,0x00,0x00,0x06,0x00,0x1E,0x00,0x00,0x00,0x00,0x00,0x04,0x00,0x24,0x00,0x00,0x00,
+      0x14,0x00,0x00,0x00,0x10,0x00,0x0C,0x00,0x07,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x08,0x00,
+      0x10,0x00,0x00,0x00,0x00,0x00,0x00,0x07,0x01,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x61,0x00,0x00,0x00
+    };
+    return bfbsData;
+  }
+  static size_t size() {
+    return 1180;
+  }
+  const uint8_t *begin() {
+    return data();
+  }
+  const uint8_t *end() {
+    return data() + size();
+  }
+};
+
+#endif  // FLATBUFFERS_GENERATED_TEST64BIT_BFBS_H_
diff --git a/tests/64bit/test_64bit_generated.h b/tests/64bit/test_64bit_generated.h
new file mode 100644
index 00000000..3bd40698
--- /dev/null
+++ b/tests/64bit/test_64bit_generated.h
@@ -0,0 +1,625 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+
+#ifndef FLATBUFFERS_GENERATED_TEST64BIT_H_
+#define FLATBUFFERS_GENERATED_TEST64BIT_H_
+
+#include "flatbuffers/flatbuffers.h"
+
+// Ensure the included flatbuffers.h is the same version as when this file was
+// generated, otherwise it may not be compatible.
+static_assert(FLATBUFFERS_VERSION_MAJOR == 23 &&
+              FLATBUFFERS_VERSION_MINOR == 5 &&
+              FLATBUFFERS_VERSION_REVISION == 8,
+             "Non-compatible flatbuffers version included");
+
+// For access to the binary schema that produced this file.
+#include "test_64bit_bfbs_generated.h"
+
+struct LeafStruct;
+
+struct WrapperTable;
+struct WrapperTableBuilder;
+struct WrapperTableT;
+
+struct RootTable;
+struct RootTableBuilder;
+struct RootTableT;
+
+bool operator==(const LeafStruct &lhs, const LeafStruct &rhs);
+bool operator!=(const LeafStruct &lhs, const LeafStruct &rhs);
+bool operator==(const WrapperTableT &lhs, const WrapperTableT &rhs);
+bool operator!=(const WrapperTableT &lhs, const WrapperTableT &rhs);
+bool operator==(const RootTableT &lhs, const RootTableT &rhs);
+bool operator!=(const RootTableT &lhs, const RootTableT &rhs);
+
+inline const ::flatbuffers::TypeTable *LeafStructTypeTable();
+
+inline const ::flatbuffers::TypeTable *WrapperTableTypeTable();
+
+inline const ::flatbuffers::TypeTable *RootTableTypeTable();
+
+FLATBUFFERS_MANUALLY_ALIGNED_STRUCT(8) LeafStruct FLATBUFFERS_FINAL_CLASS {
+ private:
+  int32_t a_;
+  int32_t padding0__;
+  double b_;
+
+ public:
+  static const ::flatbuffers::TypeTable *MiniReflectTypeTable() {
+    return LeafStructTypeTable();
+  }
+  LeafStruct()
+      : a_(0),
+        padding0__(0),
+        b_(0) {
+    (void)padding0__;
+  }
+  LeafStruct(int32_t _a, double _b)
+      : a_(::flatbuffers::EndianScalar(_a)),
+        padding0__(0),
+        b_(::flatbuffers::EndianScalar(_b)) {
+    (void)padding0__;
+  }
+  int32_t a() const {
+    return ::flatbuffers::EndianScalar(a_);
+  }
+  void mutate_a(int32_t _a) {
+    ::flatbuffers::WriteScalar(&a_, _a);
+  }
+  double b() const {
+    return ::flatbuffers::EndianScalar(b_);
+  }
+  void mutate_b(double _b) {
+    ::flatbuffers::WriteScalar(&b_, _b);
+  }
+};
+FLATBUFFERS_STRUCT_END(LeafStruct, 16);
+
+inline bool operator==(const LeafStruct &lhs, const LeafStruct &rhs) {
+  return
+      (lhs.a() == rhs.a()) &&
+      (lhs.b() == rhs.b());
+}
+
+inline bool operator!=(const LeafStruct &lhs, const LeafStruct &rhs) {
+    return !(lhs == rhs);
+}
+
+
+struct WrapperTableT : public ::flatbuffers::NativeTable {
+  typedef WrapperTable TableType;
+  std::vector<int8_t> vector{};
+};
+
+struct WrapperTable FLATBUFFERS_FINAL_CLASS : private ::flatbuffers::Table {
+  typedef WrapperTableT NativeTableType;
+  typedef WrapperTableBuilder Builder;
+  typedef RootTableBinarySchema BinarySchema;
+  static const ::flatbuffers::TypeTable *MiniReflectTypeTable() {
+    return WrapperTableTypeTable();
+  }
+  enum FlatBuffersVTableOffset FLATBUFFERS_VTABLE_UNDERLYING_TYPE {
+    VT_VECTOR = 4
+  };
+  const ::flatbuffers::Vector<int8_t> *vector() const {
+    return GetPointer64<const ::flatbuffers::Vector<int8_t> *>(VT_VECTOR);
+  }
+  ::flatbuffers::Vector<int8_t> *mutable_vector() {
+    return GetPointer64<::flatbuffers::Vector<int8_t> *>(VT_VECTOR);
+  }
+  bool Verify(::flatbuffers::Verifier &verifier) const {
+    return VerifyTableStart(verifier) &&
+           VerifyOffset64(verifier, VT_VECTOR) &&
+           verifier.VerifyVector(vector()) &&
+           verifier.EndTable();
+  }
+  WrapperTableT *UnPack(const ::flatbuffers::resolver_function_t *_resolver = nullptr) const;
+  void UnPackTo(WrapperTableT *_o, const ::flatbuffers::resolver_function_t *_resolver = nullptr) const;
+  static ::flatbuffers::Offset<WrapperTable> Pack(::flatbuffers::FlatBufferBuilder64 &_fbb, const WrapperTableT* _o, const ::flatbuffers::rehasher_function_t *_rehasher = nullptr);
+};
+
+struct WrapperTableBuilder {
+  typedef WrapperTable Table;
+  ::flatbuffers::FlatBufferBuilder64 &fbb_;
+  ::flatbuffers::uoffset_t start_;
+  void add_vector(::flatbuffers::Offset64<::flatbuffers::Vector<int8_t>> vector) {
+    fbb_.AddOffset(WrapperTable::VT_VECTOR, vector);
+  }
+  explicit WrapperTableBuilder(::flatbuffers::FlatBufferBuilder64 &_fbb)
+        : fbb_(_fbb) {
+    start_ = fbb_.StartTable();
+  }
+  ::flatbuffers::Offset<WrapperTable> Finish() {
+    const auto end = fbb_.EndTable(start_);
+    auto o = ::flatbuffers::Offset<WrapperTable>(end);
+    return o;
+  }
+};
+
+inline ::flatbuffers::Offset<WrapperTable> CreateWrapperTable(
+    ::flatbuffers::FlatBufferBuilder64 &_fbb,
+    ::flatbuffers::Offset64<::flatbuffers::Vector<int8_t>> vector = 0) {
+  WrapperTableBuilder builder_(_fbb);
+  builder_.add_vector(vector);
+  return builder_.Finish();
+}
+
+inline ::flatbuffers::Offset<WrapperTable> CreateWrapperTableDirect(
+    ::flatbuffers::FlatBufferBuilder64 &_fbb,
+    const std::vector<int8_t> *vector = nullptr) {
+  auto vector__ = vector ? _fbb.CreateVector64<::flatbuffers::Vector>(*vector) : 0;
+  return CreateWrapperTable(
+      _fbb,
+      vector__);
+}
+
+::flatbuffers::Offset<WrapperTable> CreateWrapperTable(::flatbuffers::FlatBufferBuilder64 &_fbb, const WrapperTableT *_o, const ::flatbuffers::rehasher_function_t *_rehasher = nullptr);
+
+struct RootTableT : public ::flatbuffers::NativeTable {
+  typedef RootTable TableType;
+  std::vector<uint8_t> far_vector{};
+  int32_t a = 0;
+  std::string far_string{};
+  std::vector<uint8_t> big_vector{};
+  std::string near_string{};
+  std::vector<uint8_t> nested_root{};
+  std::vector<LeafStruct> far_struct_vector{};
+  std::vector<LeafStruct> big_struct_vector{};
+  std::vector<std::unique_ptr<WrapperTableT>> many_vectors{};
+  RootTableT() = default;
+  RootTableT(const RootTableT &o);
+  RootTableT(RootTableT&&) FLATBUFFERS_NOEXCEPT = default;
+  RootTableT &operator=(RootTableT o) FLATBUFFERS_NOEXCEPT;
+};
+
+struct RootTable FLATBUFFERS_FINAL_CLASS : private ::flatbuffers::Table {
+  typedef RootTableT NativeTableType;
+  typedef RootTableBuilder Builder;
+  typedef RootTableBinarySchema BinarySchema;
+  static const ::flatbuffers::TypeTable *MiniReflectTypeTable() {
+    return RootTableTypeTable();
+  }
+  enum FlatBuffersVTableOffset FLATBUFFERS_VTABLE_UNDERLYING_TYPE {
+    VT_FAR_VECTOR = 4,
+    VT_A = 6,
+    VT_FAR_STRING = 8,
+    VT_BIG_VECTOR = 10,
+    VT_NEAR_STRING = 12,
+    VT_NESTED_ROOT = 14,
+    VT_FAR_STRUCT_VECTOR = 16,
+    VT_BIG_STRUCT_VECTOR = 18,
+    VT_MANY_VECTORS = 20
+  };
+  const ::flatbuffers::Vector<uint8_t> *far_vector() const {
+    return GetPointer64<const ::flatbuffers::Vector<uint8_t> *>(VT_FAR_VECTOR);
+  }
+  ::flatbuffers::Vector<uint8_t> *mutable_far_vector() {
+    return GetPointer64<::flatbuffers::Vector<uint8_t> *>(VT_FAR_VECTOR);
+  }
+  int32_t a() const {
+    return GetField<int32_t>(VT_A, 0);
+  }
+  bool mutate_a(int32_t _a = 0) {
+    return SetField<int32_t>(VT_A, _a, 0);
+  }
+  const ::flatbuffers::String *far_string() const {
+    return GetPointer64<const ::flatbuffers::String *>(VT_FAR_STRING);
+  }
+  ::flatbuffers::String *mutable_far_string() {
+    return GetPointer64<::flatbuffers::String *>(VT_FAR_STRING);
+  }
+  const ::flatbuffers::Vector64<uint8_t> *big_vector() const {
+    return GetPointer64<const ::flatbuffers::Vector64<uint8_t> *>(VT_BIG_VECTOR);
+  }
+  ::flatbuffers::Vector64<uint8_t> *mutable_big_vector() {
+    return GetPointer64<::flatbuffers::Vector64<uint8_t> *>(VT_BIG_VECTOR);
+  }
+  const ::flatbuffers::String *near_string() const {
+    return GetPointer<const ::flatbuffers::String *>(VT_NEAR_STRING);
+  }
+  ::flatbuffers::String *mutable_near_string() {
+    return GetPointer<::flatbuffers::String *>(VT_NEAR_STRING);
+  }
+  const ::flatbuffers::Vector64<uint8_t> *nested_root() const {
+    return GetPointer64<const ::flatbuffers::Vector64<uint8_t> *>(VT_NESTED_ROOT);
+  }
+  ::flatbuffers::Vector64<uint8_t> *mutable_nested_root() {
+    return GetPointer64<::flatbuffers::Vector64<uint8_t> *>(VT_NESTED_ROOT);
+  }
+  const RootTable *nested_root_nested_root() const {
+    const auto _f = nested_root();
+    return _f ? ::flatbuffers::GetRoot<RootTable>(_f->Data())
+              : nullptr;
+  }
+  const ::flatbuffers::Vector<const LeafStruct *> *far_struct_vector() const {
+    return GetPointer64<const ::flatbuffers::Vector<const LeafStruct *> *>(VT_FAR_STRUCT_VECTOR);
+  }
+  ::flatbuffers::Vector<const LeafStruct *> *mutable_far_struct_vector() {
+    return GetPointer64<::flatbuffers::Vector<const LeafStruct *> *>(VT_FAR_STRUCT_VECTOR);
+  }
+  const ::flatbuffers::Vector64<const LeafStruct *> *big_struct_vector() const {
+    return GetPointer64<const ::flatbuffers::Vector64<const LeafStruct *> *>(VT_BIG_STRUCT_VECTOR);
+  }
+  ::flatbuffers::Vector64<const LeafStruct *> *mutable_big_struct_vector() {
+    return GetPointer64<::flatbuffers::Vector64<const LeafStruct *> *>(VT_BIG_STRUCT_VECTOR);
+  }
+  const ::flatbuffers::Vector<::flatbuffers::Offset<WrapperTable>> *many_vectors() const {
+    return GetPointer<const ::flatbuffers::Vector<::flatbuffers::Offset<WrapperTable>> *>(VT_MANY_VECTORS);
+  }
+  ::flatbuffers::Vector<::flatbuffers::Offset<WrapperTable>> *mutable_many_vectors() {
+    return GetPointer<::flatbuffers::Vector<::flatbuffers::Offset<WrapperTable>> *>(VT_MANY_VECTORS);
+  }
+  bool Verify(::flatbuffers::Verifier &verifier) const {
+    return VerifyTableStart(verifier) &&
+           VerifyOffset64(verifier, VT_FAR_VECTOR) &&
+           verifier.VerifyVector(far_vector()) &&
+           VerifyField<int32_t>(verifier, VT_A, 4) &&
+           VerifyOffset64(verifier, VT_FAR_STRING) &&
+           verifier.VerifyString(far_string()) &&
+           VerifyOffset64(verifier, VT_BIG_VECTOR) &&
+           verifier.VerifyVector(big_vector()) &&
+           VerifyOffset(verifier, VT_NEAR_STRING) &&
+           verifier.VerifyString(near_string()) &&
+           VerifyOffset64(verifier, VT_NESTED_ROOT) &&
+           verifier.VerifyVector(nested_root()) &&
+           verifier.VerifyNestedFlatBuffer<RootTable>(nested_root(), nullptr) &&
+           VerifyOffset64(verifier, VT_FAR_STRUCT_VECTOR) &&
+           verifier.VerifyVector(far_struct_vector()) &&
+           VerifyOffset64(verifier, VT_BIG_STRUCT_VECTOR) &&
+           verifier.VerifyVector(big_struct_vector()) &&
+           VerifyOffset(verifier, VT_MANY_VECTORS) &&
+           verifier.VerifyVector(many_vectors()) &&
+           verifier.VerifyVectorOfTables(many_vectors()) &&
+           verifier.EndTable();
+  }
+  RootTableT *UnPack(const ::flatbuffers::resolver_function_t *_resolver = nullptr) const;
+  void UnPackTo(RootTableT *_o, const ::flatbuffers::resolver_function_t *_resolver = nullptr) const;
+  static ::flatbuffers::Offset<RootTable> Pack(::flatbuffers::FlatBufferBuilder64 &_fbb, const RootTableT* _o, const ::flatbuffers::rehasher_function_t *_rehasher = nullptr);
+};
+
+struct RootTableBuilder {
+  typedef RootTable Table;
+  ::flatbuffers::FlatBufferBuilder64 &fbb_;
+  ::flatbuffers::uoffset_t start_;
+  void add_far_vector(::flatbuffers::Offset64<::flatbuffers::Vector<uint8_t>> far_vector) {
+    fbb_.AddOffset(RootTable::VT_FAR_VECTOR, far_vector);
+  }
+  void add_a(int32_t a) {
+    fbb_.AddElement<int32_t>(RootTable::VT_A, a, 0);
+  }
+  void add_far_string(::flatbuffers::Offset64<::flatbuffers::String> far_string) {
+    fbb_.AddOffset(RootTable::VT_FAR_STRING, far_string);
+  }
+  void add_big_vector(::flatbuffers::Offset64<::flatbuffers::Vector64<uint8_t>> big_vector) {
+    fbb_.AddOffset(RootTable::VT_BIG_VECTOR, big_vector);
+  }
+  void add_near_string(::flatbuffers::Offset<::flatbuffers::String> near_string) {
+    fbb_.AddOffset(RootTable::VT_NEAR_STRING, near_string);
+  }
+  void add_nested_root(::flatbuffers::Offset64<::flatbuffers::Vector64<uint8_t>> nested_root) {
+    fbb_.AddOffset(RootTable::VT_NESTED_ROOT, nested_root);
+  }
+  void add_far_struct_vector(::flatbuffers::Offset64<::flatbuffers::Vector<const LeafStruct *>> far_struct_vector) {
+    fbb_.AddOffset(RootTable::VT_FAR_STRUCT_VECTOR, far_struct_vector);
+  }
+  void add_big_struct_vector(::flatbuffers::Offset64<::flatbuffers::Vector64<const LeafStruct *>> big_struct_vector) {
+    fbb_.AddOffset(RootTable::VT_BIG_STRUCT_VECTOR, big_struct_vector);
+  }
+  void add_many_vectors(::flatbuffers::Offset<::flatbuffers::Vector<::flatbuffers::Offset<WrapperTable>>> many_vectors) {
+    fbb_.AddOffset(RootTable::VT_MANY_VECTORS, many_vectors);
+  }
+  explicit RootTableBuilder(::flatbuffers::FlatBufferBuilder64 &_fbb)
+        : fbb_(_fbb) {
+    start_ = fbb_.StartTable();
+  }
+  ::flatbuffers::Offset<RootTable> Finish() {
+    const auto end = fbb_.EndTable(start_);
+    auto o = ::flatbuffers::Offset<RootTable>(end);
+    return o;
+  }
+};
+
+inline ::flatbuffers::Offset<RootTable> CreateRootTable(
+    ::flatbuffers::FlatBufferBuilder64 &_fbb,
+    ::flatbuffers::Offset64<::flatbuffers::Vector<uint8_t>> far_vector = 0,
+    int32_t a = 0,
+    ::flatbuffers::Offset64<::flatbuffers::String> far_string = 0,
+    ::flatbuffers::Offset64<::flatbuffers::Vector64<uint8_t>> big_vector = 0,
+    ::flatbuffers::Offset<::flatbuffers::String> near_string = 0,
+    ::flatbuffers::Offset64<::flatbuffers::Vector64<uint8_t>> nested_root = 0,
+    ::flatbuffers::Offset64<::flatbuffers::Vector<const LeafStruct *>> far_struct_vector = 0,
+    ::flatbuffers::Offset64<::flatbuffers::Vector64<const LeafStruct *>> big_struct_vector = 0,
+    ::flatbuffers::Offset<::flatbuffers::Vector<::flatbuffers::Offset<WrapperTable>>> many_vectors = 0) {
+  RootTableBuilder builder_(_fbb);
+  builder_.add_big_struct_vector(big_struct_vector);
+  builder_.add_nested_root(nested_root);
+  builder_.add_big_vector(big_vector);
+  builder_.add_many_vectors(many_vectors);
+  builder_.add_far_struct_vector(far_struct_vector);
+  builder_.add_near_string(near_string);
+  builder_.add_far_string(far_string);
+  builder_.add_a(a);
+  builder_.add_far_vector(far_vector);
+  return builder_.Finish();
+}
+
+inline ::flatbuffers::Offset<RootTable> CreateRootTableDirect(
+    ::flatbuffers::FlatBufferBuilder64 &_fbb,
+    const std::vector<uint8_t> *far_vector = nullptr,
+    int32_t a = 0,
+    const char *far_string = nullptr,
+    const std::vector<uint8_t> *big_vector = nullptr,
+    const char *near_string = nullptr,
+    const std::vector<uint8_t> *nested_root = nullptr,
+    const std::vector<LeafStruct> *far_struct_vector = nullptr,
+    const std::vector<LeafStruct> *big_struct_vector = nullptr,
+    const std::vector<::flatbuffers::Offset<WrapperTable>> *many_vectors = nullptr) {
+  auto far_vector__ = far_vector ? _fbb.CreateVector64<::flatbuffers::Vector>(*far_vector) : 0;
+  auto far_string__ = far_string ? _fbb.CreateString<::flatbuffers::Offset64>(far_string) : 0;
+  auto big_vector__ = big_vector ? _fbb.CreateVector64(*big_vector) : 0;
+  auto nested_root__ = nested_root ? _fbb.CreateVector64(*nested_root) : 0;
+  auto far_struct_vector__ = far_struct_vector ? _fbb.CreateVectorOfStructs64<::flatbuffers::Vector>(*far_struct_vector) : 0;
+  auto big_struct_vector__ = big_struct_vector ? _fbb.CreateVectorOfStructs64(*big_struct_vector) : 0;
+  auto near_string__ = near_string ? _fbb.CreateString(near_string) : 0;
+  auto many_vectors__ = many_vectors ? _fbb.CreateVector<::flatbuffers::Offset<WrapperTable>>(*many_vectors) : 0;
+  return CreateRootTable(
+      _fbb,
+      far_vector__,
+      a,
+      far_string__,
+      big_vector__,
+      near_string__,
+      nested_root__,
+      far_struct_vector__,
+      big_struct_vector__,
+      many_vectors__);
+}
+
+::flatbuffers::Offset<RootTable> CreateRootTable(::flatbuffers::FlatBufferBuilder64 &_fbb, const RootTableT *_o, const ::flatbuffers::rehasher_function_t *_rehasher = nullptr);
+
+
+inline bool operator==(const WrapperTableT &lhs, const WrapperTableT &rhs) {
+  return
+      (lhs.vector == rhs.vector);
+}
+
+inline bool operator!=(const WrapperTableT &lhs, const WrapperTableT &rhs) {
+    return !(lhs == rhs);
+}
+
+
+inline WrapperTableT *WrapperTable::UnPack(const ::flatbuffers::resolver_function_t *_resolver) const {
+  auto _o = std::unique_ptr<WrapperTableT>(new WrapperTableT());
+  UnPackTo(_o.get(), _resolver);
+  return _o.release();
+}
+
+inline void WrapperTable::UnPackTo(WrapperTableT *_o, const ::flatbuffers::resolver_function_t *_resolver) const {
+  (void)_o;
+  (void)_resolver;
+  { auto _e = vector(); if (_e) { _o->vector.resize(_e->size()); std::copy(_e->begin(), _e->end(), _o->vector.begin()); } }
+}
+
+inline ::flatbuffers::Offset<WrapperTable> WrapperTable::Pack(::flatbuffers::FlatBufferBuilder64 &_fbb, const WrapperTableT* _o, const ::flatbuffers::rehasher_function_t *_rehasher) {
+  return CreateWrapperTable(_fbb, _o, _rehasher);
+}
+
+inline ::flatbuffers::Offset<WrapperTable> CreateWrapperTable(::flatbuffers::FlatBufferBuilder64 &_fbb, const WrapperTableT *_o, const ::flatbuffers::rehasher_function_t *_rehasher) {
+  (void)_rehasher;
+  (void)_o;
+  struct _VectorArgs { ::flatbuffers::FlatBufferBuilder64 *__fbb; const WrapperTableT* __o; const ::flatbuffers::rehasher_function_t *__rehasher; } _va = { &_fbb, _o, _rehasher}; (void)_va;
+  auto _vector = _o->vector.size() ? _fbb.CreateVector64<::flatbuffers::Vector>(_o->vector) : 0;
+  return CreateWrapperTable(
+      _fbb,
+      _vector);
+}
+
+
+inline bool operator==(const RootTableT &lhs, const RootTableT &rhs) {
+  return
+      (lhs.far_vector == rhs.far_vector) &&
+      (lhs.a == rhs.a) &&
+      (lhs.far_string == rhs.far_string) &&
+      (lhs.big_vector == rhs.big_vector) &&
+      (lhs.near_string == rhs.near_string) &&
+      (lhs.nested_root == rhs.nested_root) &&
+      (lhs.far_struct_vector == rhs.far_struct_vector) &&
+      (lhs.big_struct_vector == rhs.big_struct_vector) &&
+      (lhs.many_vectors.size() == rhs.many_vectors.size() && std::equal(lhs.many_vectors.cbegin(), lhs.many_vectors.cend(), rhs.many_vectors.cbegin(), [](std::unique_ptr<WrapperTableT> const &a, std::unique_ptr<WrapperTableT> const &b) { return (a == b) || (a && b && *a == *b); }));
+}
+
+inline bool operator!=(const RootTableT &lhs, const RootTableT &rhs) {
+    return !(lhs == rhs);
+}
+
+
+inline RootTableT::RootTableT(const RootTableT &o)
+      : far_vector(o.far_vector),
+        a(o.a),
+        far_string(o.far_string),
+        big_vector(o.big_vector),
+        near_string(o.near_string),
+        nested_root(o.nested_root),
+        far_struct_vector(o.far_struct_vector),
+        big_struct_vector(o.big_struct_vector) {
+  many_vectors.reserve(o.many_vectors.size());
+  for (const auto &many_vectors_ : o.many_vectors) { many_vectors.emplace_back((many_vectors_) ? new WrapperTableT(*many_vectors_) : nullptr); }
+}
+
+inline RootTableT &RootTableT::operator=(RootTableT o) FLATBUFFERS_NOEXCEPT {
+  std::swap(far_vector, o.far_vector);
+  std::swap(a, o.a);
+  std::swap(far_string, o.far_string);
+  std::swap(big_vector, o.big_vector);
+  std::swap(near_string, o.near_string);
+  std::swap(nested_root, o.nested_root);
+  std::swap(far_struct_vector, o.far_struct_vector);
+  std::swap(big_struct_vector, o.big_struct_vector);
+  std::swap(many_vectors, o.many_vectors);
+  return *this;
+}
+
+inline RootTableT *RootTable::UnPack(const ::flatbuffers::resolver_function_t *_resolver) const {
+  auto _o = std::unique_ptr<RootTableT>(new RootTableT());
+  UnPackTo(_o.get(), _resolver);
+  return _o.release();
+}
+
+inline void RootTable::UnPackTo(RootTableT *_o, const ::flatbuffers::resolver_function_t *_resolver) const {
+  (void)_o;
+  (void)_resolver;
+  { auto _e = far_vector(); if (_e) { _o->far_vector.resize(_e->size()); std::copy(_e->begin(), _e->end(), _o->far_vector.begin()); } }
+  { auto _e = a(); _o->a = _e; }
+  { auto _e = far_string(); if (_e) _o->far_string = _e->str(); }
+  { auto _e = big_vector(); if (_e) { _o->big_vector.resize(_e->size()); std::copy(_e->begin(), _e->end(), _o->big_vector.begin()); } }
+  { auto _e = near_string(); if (_e) _o->near_string = _e->str(); }
+  { auto _e = nested_root(); if (_e) { _o->nested_root.resize(_e->size()); std::copy(_e->begin(), _e->end(), _o->nested_root.begin()); } }
+  { auto _e = far_struct_vector(); if (_e) { _o->far_struct_vector.resize(_e->size()); for (::flatbuffers::uoffset_t _i = 0; _i < _e->size(); _i++) { _o->far_struct_vector[_i] = *_e->Get(_i); } } else { _o->far_struct_vector.resize(0); } }
+  { auto _e = big_struct_vector(); if (_e) { _o->big_struct_vector.resize(_e->size()); for (::flatbuffers::uoffset64_t _i = 0; _i < _e->size(); _i++) { _o->big_struct_vector[_i] = *_e->Get(_i); } } else { _o->big_struct_vector.resize(0); } }
+  { auto _e = many_vectors(); if (_e) { _o->many_vectors.resize(_e->size()); for (::flatbuffers::uoffset_t _i = 0; _i < _e->size(); _i++) { if(_o->many_vectors[_i]) { _e->Get(_i)->UnPackTo(_o->many_vectors[_i].get(), _resolver); } else { _o->many_vectors[_i] = std::unique_ptr<WrapperTableT>(_e->Get(_i)->UnPack(_resolver)); }; } } else { _o->many_vectors.resize(0); } }
+}
+
+inline ::flatbuffers::Offset<RootTable> RootTable::Pack(::flatbuffers::FlatBufferBuilder64 &_fbb, const RootTableT* _o, const ::flatbuffers::rehasher_function_t *_rehasher) {
+  return CreateRootTable(_fbb, _o, _rehasher);
+}
+
+inline ::flatbuffers::Offset<RootTable> CreateRootTable(::flatbuffers::FlatBufferBuilder64 &_fbb, const RootTableT *_o, const ::flatbuffers::rehasher_function_t *_rehasher) {
+  (void)_rehasher;
+  (void)_o;
+  struct _VectorArgs { ::flatbuffers::FlatBufferBuilder64 *__fbb; const RootTableT* __o; const ::flatbuffers::rehasher_function_t *__rehasher; } _va = { &_fbb, _o, _rehasher}; (void)_va;
+  auto _far_vector = _o->far_vector.size() ? _fbb.CreateVector64<::flatbuffers::Vector>(_o->far_vector) : 0;
+  auto _a = _o->a;
+  auto _far_string = _o->far_string.empty() ? 0 : _fbb.CreateString<::flatbuffers::Offset64>(_o->far_string);
+  auto _big_vector = _o->big_vector.size() ? _fbb.CreateVector64(_o->big_vector) : 0;
+  auto _near_string = _o->near_string.empty() ? 0 : _fbb.CreateString(_o->near_string);
+  auto _nested_root = _o->nested_root.size() ? _fbb.CreateVector64(_o->nested_root) : 0;
+  auto _far_struct_vector = _o->far_struct_vector.size() ? _fbb.CreateVectorOfStructs64<::flatbuffers::Vector>(_o->far_struct_vector) : 0;
+  auto _big_struct_vector = _o->big_struct_vector.size() ? _fbb.CreateVectorOfStructs64(_o->big_struct_vector) : 0;
+  auto _many_vectors = _o->many_vectors.size() ? _fbb.CreateVector<::flatbuffers::Offset<WrapperTable>> (_o->many_vectors.size(), [](size_t i, _VectorArgs *__va) { return CreateWrapperTable(*__va->__fbb, __va->__o->many_vectors[i].get(), __va->__rehasher); }, &_va ) : 0;
+  return CreateRootTable(
+      _fbb,
+      _far_vector,
+      _a,
+      _far_string,
+      _big_vector,
+      _near_string,
+      _nested_root,
+      _far_struct_vector,
+      _big_struct_vector,
+      _many_vectors);
+}
+
+inline const ::flatbuffers::TypeTable *LeafStructTypeTable() {
+  static const ::flatbuffers::TypeCode type_codes[] = {
+    { ::flatbuffers::ET_INT, 0, -1 },
+    { ::flatbuffers::ET_DOUBLE, 0, -1 }
+  };
+  static const int64_t values[] = { 0, 8, 16 };
+  static const char * const names[] = {
+    "a",
+    "b"
+  };
+  static const ::flatbuffers::TypeTable tt = {
+    ::flatbuffers::ST_STRUCT, 2, type_codes, nullptr, nullptr, values, names
+  };
+  return &tt;
+}
+
+inline const ::flatbuffers::TypeTable *WrapperTableTypeTable() {
+  static const ::flatbuffers::TypeCode type_codes[] = {
+    { ::flatbuffers::ET_CHAR, 1, -1 }
+  };
+  static const char * const names[] = {
+    "vector"
+  };
+  static const ::flatbuffers::TypeTable tt = {
+    ::flatbuffers::ST_TABLE, 1, type_codes, nullptr, nullptr, nullptr, names
+  };
+  return &tt;
+}
+
+inline const ::flatbuffers::TypeTable *RootTableTypeTable() {
+  static const ::flatbuffers::TypeCode type_codes[] = {
+    { ::flatbuffers::ET_UCHAR, 1, -1 },
+    { ::flatbuffers::ET_INT, 0, -1 },
+    { ::flatbuffers::ET_STRING, 0, -1 },
+    { ::flatbuffers::ET_UCHAR, 1, -1 },
+    { ::flatbuffers::ET_STRING, 0, -1 },
+    { ::flatbuffers::ET_UCHAR, 1, -1 },
+    { ::flatbuffers::ET_SEQUENCE, 1, 0 },
+    { ::flatbuffers::ET_SEQUENCE, 1, 0 },
+    { ::flatbuffers::ET_SEQUENCE, 1, 1 }
+  };
+  static const ::flatbuffers::TypeFunction type_refs[] = {
+    LeafStructTypeTable,
+    WrapperTableTypeTable
+  };
+  static const char * const names[] = {
+    "far_vector",
+    "a",
+    "far_string",
+    "big_vector",
+    "near_string",
+    "nested_root",
+    "far_struct_vector",
+    "big_struct_vector",
+    "many_vectors"
+  };
+  static const ::flatbuffers::TypeTable tt = {
+    ::flatbuffers::ST_TABLE, 9, type_codes, type_refs, nullptr, nullptr, names
+  };
+  return &tt;
+}
+
+inline const RootTable *GetRootTable(const void *buf) {
+  return ::flatbuffers::GetRoot<RootTable>(buf);
+}
+
+inline const RootTable *GetSizePrefixedRootTable(const void *buf) {
+  return ::flatbuffers::GetSizePrefixedRoot<RootTable,::flatbuffers::uoffset64_t>(buf);
+}
+
+inline RootTable *GetMutableRootTable(void *buf) {
+  return ::flatbuffers::GetMutableRoot<RootTable>(buf);
+}
+
+inline RootTable *GetMutableSizePrefixedRootTable(void *buf) {
+  return ::flatbuffers::GetMutableSizePrefixedRoot<RootTable,::flatbuffers::uoffset64_t>(buf);
+}
+
+inline bool VerifyRootTableBuffer(
+    ::flatbuffers::Verifier &verifier) {
+  return verifier.VerifyBuffer<RootTable>(nullptr);
+}
+
+inline bool VerifySizePrefixedRootTableBuffer(
+    ::flatbuffers::Verifier &verifier) {
+  return verifier.VerifySizePrefixedBuffer<RootTable,::flatbuffers::uoffset64_t>(nullptr);
+}
+
+inline void FinishRootTableBuffer(
+    ::flatbuffers::FlatBufferBuilder64 &fbb,
+    ::flatbuffers::Offset<RootTable> root) {
+  fbb.Finish(root);
+}
+
+inline void FinishSizePrefixedRootTableBuffer(
+    ::flatbuffers::FlatBufferBuilder64 &fbb,
+    ::flatbuffers::Offset<RootTable> root) {
+  fbb.FinishSizePrefixed(root);
+}
+
+inline std::unique_ptr<RootTableT> UnPackRootTable(
+    const void *buf,
+    const ::flatbuffers::resolver_function_t *res = nullptr) {
+  return std::unique_ptr<RootTableT>(GetRootTable(buf)->UnPack(res));
+}
+
+inline std::unique_ptr<RootTableT> UnPackSizePrefixedRootTable(
+    const void *buf,
+    const ::flatbuffers::resolver_function_t *res = nullptr) {
+  return std::unique_ptr<RootTableT>(GetSizePrefixedRootTable(buf)->UnPack(res));
+}
+
+#endif  // FLATBUFFERS_GENERATED_TEST64BIT_H_
diff --git a/tests/BUILD.bazel b/tests/BUILD.bazel
index 96fd9c1e..923890f6 100644
--- a/tests/BUILD.bazel
+++ b/tests/BUILD.bazel
@@ -20,6 +20,12 @@ cc_test(
     name = "flatbuffers_test",
     testonly = 1,
     srcs = [
+        "64bit/evolution/v1_generated.h",
+        "64bit/evolution/v2_generated.h",
+        "64bit/offset64_test.cpp",
+        "64bit/offset64_test.h",
+        "64bit/test_64bit_bfbs_generated.h",
+        "64bit/test_64bit_generated.h",
         "alignment_test.cpp",
         "alignment_test.h",
         "alignment_test_generated.h",
diff --git a/tests/MyGame/Example/Monster.php b/tests/MyGame/Example/Monster.php
index 29976e4a..44649403 100644
--- a/tests/MyGame/Example/Monster.php
+++ b/tests/MyGame/Example/Monster.php
@@ -910,7 +910,7 @@ class Monster extends Table
 
     /**
      * @param FlatBufferBuilder $builder
-     * @param int
+     * @param VectorOffset
      * @return void
      */
     public static function addPos(FlatBufferBuilder $builder, $pos)
@@ -1111,7 +1111,7 @@ class Monster extends Table
 
     /**
      * @param FlatBufferBuilder $builder
-     * @param int
+     * @param VectorOffset
      * @return void
      */
     public static function addEnemy(FlatBufferBuilder $builder, $enemy)
@@ -1155,7 +1155,7 @@ class Monster extends Table
 
     /**
      * @param FlatBufferBuilder $builder
-     * @param int
+     * @param VectorOffset
      * @return void
      */
     public static function addTestempty(FlatBufferBuilder $builder, $testempty)
@@ -1523,7 +1523,7 @@ class Monster extends Table
 
     /**
      * @param FlatBufferBuilder $builder
-     * @param int
+     * @param VectorOffset
      * @return void
      */
     public static function addParentNamespaceTest(FlatBufferBuilder $builder, $parentNamespaceTest)
@@ -1875,7 +1875,7 @@ class Monster extends Table
 
     /**
      * @param FlatBufferBuilder $builder
-     * @param int
+     * @param VectorOffset
      * @return void
      */
     public static function addNativeInline(FlatBufferBuilder $builder, $nativeInline)
diff --git a/tests/evolution_test.cpp b/tests/evolution_test.cpp
index 6c23d3fe..6ed2f574 100644
--- a/tests/evolution_test.cpp
+++ b/tests/evolution_test.cpp
@@ -80,7 +80,6 @@ void EvolutionTest(const std::string &tests_data_path) {
 #endif
 }
 
-
 void ConformTest() {
   const char ref[] = "table T { A:int; } enum E:byte { A }";
 
@@ -111,9 +110,41 @@ void ConformTest() {
   const char ref2[] = "enum E:byte { A } table T2 { f:E; } ";
   test_conform(ref2, "enum E:int32 { A } table T2 { df:byte; f:E; }",
                "field renamed to different type: T2.df (renamed from T2.f)");
+
+  // Check conformity for Offset64-related changes.
+  {
+    const char ref[] = "table T { a:[uint8]; b:string; }";
+
+    // Adding a 'vector64' changes the type.
+    test_conform(ref, "table T { a:[uint8] (vector64); b:string; }",
+                 "types differ for field: T.a");
+
+    // Adding a 'offset64' to the vector changes the type.
+    test_conform(ref, "table T { a:[uint8] (offset64); b:string; }",
+                 "offset types differ for field: T.a");
+
+    // Adding a 'offset64' to the string also changes the type.
+    test_conform(ref, "table T { a:[uint8]; b:string (offset64); }",
+                 "offset types differ for field: T.b");
+
+    // Now try the opposite direction of removing an attribute from an existing
+    // field.
+
+    // Removing a 'vector64' changes the type.
+    test_conform("table T { a:[uint8] (vector64); b:string; }", ref,
+                 "types differ for field: T.a");
+
+    // Removing a 'offset64' to the string also changes the type.
+    test_conform("table T { a:[uint8] (offset64); b:string; }", ref,
+                 "offset types differ for field: T.a");
+
+    // Remove a 'offset64' to the string also changes the type.
+    test_conform("table T { a:[uint8]; b:string (offset64); }", ref,
+                 "offset types differ for field: T.b");
+  }
 }
 
-void UnionDeprecationTest(const std::string& tests_data_path) {
+void UnionDeprecationTest(const std::string &tests_data_path) {
   const int NUM_VERSIONS = 2;
   std::string schemas[NUM_VERSIONS];
   std::string jsonfiles[NUM_VERSIONS];
diff --git a/tests/fuzzer/.gitignore b/tests/fuzzer/.gitignore
index 2e4d1d19..720146cf 100644
--- a/tests/fuzzer/.gitignore
+++ b/tests/fuzzer/.gitignore
@@ -15,4 +15,6 @@ fuzz-*.log
 annotated_binary.bfbs
 annotated_binary.bin
 
+test_64bit.bin
+
 monster_test.bfbs
\ No newline at end of file
diff --git a/tests/fuzzer/CMakeLists.txt b/tests/fuzzer/CMakeLists.txt
index 63bda687..b0c4ae6d 100644
--- a/tests/fuzzer/CMakeLists.txt
+++ b/tests/fuzzer/CMakeLists.txt
@@ -117,6 +117,7 @@ set(FlatBuffers_Library_SRCS
     ${FLATBUFFERS_DIR}/src/binary_annotator.cpp
     ${FLATBUFFERS_DIR}/src/util.cpp
     ${FLATBUFFERS_DIR}/tests/test_assert.cpp
+    ${FLATBUFFERS_DIR}/tests/64bit/test_64bit_bfbs_generated.h
 )
 
 include_directories(${FLATBUFFERS_DIR}/include)
@@ -175,6 +176,16 @@ add_custom_command(
   ${CMAKE_CURRENT_BINARY_DIR}/seed_annotator/annotated_binary.bin
 )
 
+add_executable(64bit_fuzzer flatbuffers_64bit_fuzzer.cc)
+target_link_libraries(64bit_fuzzer PRIVATE flatbuffers_fuzzed)
+add_custom_command(
+  TARGET 64bit_fuzzer PRE_BUILD
+
+  COMMAND ${CMAKE_COMMAND} -E copy
+  ${CMAKE_SOURCE_DIR}/../64bit/test_64bit.bin
+  ${CMAKE_CURRENT_BINARY_DIR}/seed_64bit/test_64bit.bin
+)
+
 # Build debugger for weird cases found with fuzzer.
 if(BUILD_DEBUGGER)
   add_library(flatbuffers_nonfuzz STATIC ${FlatBuffers_Library_SRCS})
diff --git a/tests/fuzzer/flatbuffers_64bit_fuzzer.cc b/tests/fuzzer/flatbuffers_64bit_fuzzer.cc
new file mode 100644
index 00000000..efb629d3
--- /dev/null
+++ b/tests/fuzzer/flatbuffers_64bit_fuzzer.cc
@@ -0,0 +1,121 @@
+#include <cstdint>
+#include <filesystem>
+#include <type_traits>
+
+#include "64bit/test_64bit_bfbs_generated.h"
+#include "64bit/test_64bit_generated.h"
+#include "flatbuffers/base.h"
+#include "flatbuffers/flatbuffer_builder.h"
+#include "flatbuffers/flatbuffers.h"
+#include "flatbuffers/reflection.h"
+#include "flatbuffers/verifier.h"
+#include "test_assert.h"
+#include "test_init.h"
+
+OneTimeTestInit OneTimeTestInit::one_time_init_;
+
+static RootTableBinarySchema schema;
+
+static constexpr uint8_t flags_sized_prefixed = 0b00000001;
+
+static const uint64_t kFnvPrime = 0x00000100000001b3ULL;
+static const uint64_t kOffsetBasis = 0xcbf29ce484222645ULL;
+
+namespace flatbuffers {
+
+template<typename T, typename = std::enable_if_t<std::is_integral_v<T>>>
+uint64_t Hash(T value, uint64_t hash) {
+  return (hash * kFnvPrime) ^ value;
+}
+
+uint64_t Hash(double value, uint64_t hash) {
+  static_assert(sizeof(double) == sizeof(uint64_t));
+  return (hash * kFnvPrime) ^ static_cast<uint64_t>(value);
+}
+
+uint64_t Hash(const flatbuffers::String *value, uint64_t hash) {
+  if (value == nullptr) { return hash * kFnvPrime; }
+  for (auto &c : value->str()) { hash = Hash(static_cast<uint8_t>(c), hash); }
+  return hash;
+}
+
+uint64_t Hash(const LeafStruct *value, uint64_t hash) {
+  if (value == nullptr) { return hash * kFnvPrime; }
+  hash = Hash(value->a(), hash);
+  hash = Hash(value->b(), hash);
+  return hash;
+}
+
+template<typename T> uint64_t Hash(const Vector<T> *value, uint64_t hash) {
+  if (value == nullptr) { return hash * kFnvPrime; }
+  for (const T c : *value) { hash = Hash(c, hash); }
+  return hash;
+}
+
+template<typename T> uint64_t Hash(const Vector64<T> *value, uint64_t hash) {
+  if (value == nullptr) { return hash * kFnvPrime; }
+  for (const T c : *value) { hash = Hash(c, hash); }
+  return hash;
+}
+
+uint64_t Hash(const RootTable *value, uint64_t hash) {
+  if (value == nullptr) { return hash * kFnvPrime; }
+  // Hash all the fields so we can exercise all parts of the code.
+  hash = Hash(value->far_vector(), hash);
+  hash = Hash(value->a(), hash);
+  hash = Hash(value->far_string(), hash);
+  hash = Hash(value->big_vector(), hash);
+  hash = Hash(value->near_string(), hash);
+  hash = Hash(value->nested_root(), hash);
+  hash = Hash(value->far_struct_vector(), hash);
+  hash = Hash(value->big_struct_vector(), hash);
+  return hash;
+}
+
+static int AccessBuffer(const uint8_t *data, size_t size,
+                        bool is_size_prefixed) {
+  const RootTable *root_table =
+      is_size_prefixed ? GetSizePrefixedRootTable(data) : GetRootTable(data);
+  TEST_NOTNULL(root_table);
+
+  uint64_t hash = kOffsetBasis;
+  hash = Hash(root_table, hash);
+  hash = Hash(root_table->nested_root_nested_root(), hash);
+
+  return 0;
+}
+
+extern "C" int LLVMFuzzerInitialize(int *, char ***argv) {
+  Verifier verifier(schema.begin(), schema.size());
+  TEST_EQ(true, reflection::VerifySchemaBuffer(verifier));
+
+  return 0;
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+  if (size < FLATBUFFERS_MIN_BUFFER_SIZE) { return 0; }
+
+  // Take the first bit of data as a flag to control things.
+  const uint8_t flags = data[0];
+  data++;
+  size--;
+
+  Verifier::Options options;
+  options.assert = true;
+  options.check_alignment = true;
+  options.check_nested_flatbuffers = true;
+
+  Verifier verifier(data, size, options);
+
+  const bool is_size_prefixed = flags & flags_sized_prefixed;
+
+  // Filter out data that isn't valid.
+  if ((is_size_prefixed && !VerifySizePrefixedRootTableBuffer(verifier)) ||
+      !VerifyRootTableBuffer(verifier)) {
+    return 0;
+  }
+
+  return AccessBuffer(data, size, is_size_prefixed);
+}
+
+}  // namespace flatbuffers
\ No newline at end of file
diff --git a/tests/fuzzer/flatbuffers_annotator_fuzzer.cc b/tests/fuzzer/flatbuffers_annotator_fuzzer.cc
index 7ff43137..08c1e0bc 100644
--- a/tests/fuzzer/flatbuffers_annotator_fuzzer.cc
+++ b/tests/fuzzer/flatbuffers_annotator_fuzzer.cc
@@ -46,7 +46,7 @@ extern "C" int LLVMFuzzerInitialize(int *, char ***argv) {
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
   flatbuffers::BinaryAnnotator annotator(schema_bfbs_, schema_bfbs_length_,
-                                         data, size);
+                                         data, size, false);
 
   annotator.Annotate();
   return 0;
diff --git a/tests/parser_test.cpp b/tests/parser_test.cpp
index 7bcf62bf..83c67e85 100644
--- a/tests/parser_test.cpp
+++ b/tests/parser_test.cpp
@@ -16,8 +16,9 @@ static const auto infinity_f = std::numeric_limits<float>::infinity();
 static const auto infinity_d = std::numeric_limits<double>::infinity();
 
 // Test that parser errors are actually generated.
-static void TestError_(const char *src, const char *error_substr, bool strict_json,
-                const char *file, int line, const char *func) {
+static void TestError_(const char *src, const char *error_substr,
+                       bool strict_json, const char *file, int line,
+                       const char *func) {
   flatbuffers::IDLOptions opts;
   opts.strict_json = strict_json;
   flatbuffers::Parser parser(opts);
@@ -32,8 +33,8 @@ static void TestError_(const char *src, const char *error_substr, bool strict_js
   }
 }
 
-static void TestError_(const char *src, const char *error_substr, const char *file,
-                int line, const char *func) {
+static void TestError_(const char *src, const char *error_substr,
+                       const char *file, int line, const char *func) {
   TestError_(src, error_substr, false, file, line, func);
 }
 
@@ -47,7 +48,7 @@ static void TestError_(const char *src, const char *error_substr, const char *fi
 
 static bool FloatCompare(float a, float b) { return fabs(a - b) < 0.001; }
 
-} // namespace
+}  // namespace
 
 // Test that parsing errors occur as we'd expect.
 // Also useful for coverage, making sure these paths are run.
@@ -124,6 +125,34 @@ void ErrorTest() {
   // An identifier can't start from sign (+|-)
   TestError("table X { -Y: int; } root_type Y: {Y:1.0}", "identifier");
   TestError("table X { +Y: int; } root_type Y: {Y:1.0}", "identifier");
+
+  // Offset64
+  TestError("table X { a:int (vector64); }", "`vector64` attribute");
+  TestError("table X { a:int (offset64); }", "`offset64` attribute");
+  TestError("table X { a:string (vector64); }", "`vector64` attribute");
+  TestError("table y { a:int; } table X { a:y (offset64); }",
+            "`offset64` attribute");
+  TestError("struct y { a:int; } table X { a:y (offset64); }",
+            "`offset64` attribute");
+  TestError("table y { a:int; } table X { a:y (vector64); }",
+            "`vector64` attribute");
+  TestError("union Y { } table X { ys:Y (offset64); }", "`offset64` attribute");
+
+  TestError("table Y { a:int; } table X { ys:[Y] (offset64); }",
+            "only vectors of scalars are allowed to be 64-bit.");
+  TestError("table Y { a:int; } table X { ys:[Y] (vector64); }",
+            "only vectors of scalars are allowed to be 64-bit.");
+  TestError("union Y { } table X { ys:[Y] (vector64); }",
+            "only vectors of scalars are allowed to be 64-bit.");
+
+  // TOOD(derekbailey): the following three could be allowed once the code gen
+  // supports the output.
+  TestError("table X { y:[string] (offset64); }",
+            "only vectors of scalars are allowed to be 64-bit.");
+  TestError("table X { y:[string] (vector64); }",
+            "only vectors of scalars are allowed to be 64-bit.");
+  TestError("enum X:byte {Z} table X { y:[X] (offset64); }",
+            "only vectors of scalars are allowed to be 64-bit.");
 }
 
 void EnumOutOfRangeTest() {
@@ -776,8 +805,6 @@ void UnicodeSurrogatesTest() {
   TEST_EQ_STR(string->c_str(), "\xF0\x9F\x92\xA9");
 }
 
-
-
 void UnknownFieldsTest() {
   flatbuffers::IDLOptions opts;
   opts.skip_unexpected_fields_in_json = true;
diff --git a/tests/test.cpp b/tests/test.cpp
index 1faf33e4..ec60251a 100644
--- a/tests/test.cpp
+++ b/tests/test.cpp
@@ -42,7 +42,7 @@
 #if !defined(_MSC_VER) || _MSC_VER >= 1700
 #  include "arrays_test_generated.h"
 #endif
-
+#include "64bit/offset64_test.h"
 #include "flexbuffers_test.h"
 #include "is_quiet_nan.h"
 #include "monster_test_bfbs_generated.h"  // Generated using --bfbs-comments --bfbs-builtins --cpp --bfbs-gen-embed
@@ -74,7 +74,7 @@ static_assert(flatbuffers::is_same<uint8_t, char>::value ||
 using namespace MyGame::Example;
 
 void TriviallyCopyableTest() {
-// clang-format off
+  // clang-format off
   #if __GNUG__ && __GNUC__ < 5 && \
       !(defined(__clang__) && __clang_major__ >= 16)
     TEST_EQ(__has_trivial_copy(Vec3), true);
@@ -1540,6 +1540,17 @@ void DoNotRequireEofTest(const std::string &tests_data_path) {
 }
 #endif
 
+static void Offset64Tests() {
+  Offset64Test();
+  Offset64SerializedFirst();
+  Offset64NestedFlatBuffer();
+  Offset64CreateDirect();
+  Offset64Evolution();
+  Offset64VectorOfStructs();
+  Offset64SizePrefix();
+  Offset64ManyVectors();
+}
+
 int FlatBufferTests(const std::string &tests_data_path) {
   // Run our various test suites:
 
@@ -1651,6 +1662,7 @@ int FlatBufferTests(const std::string &tests_data_path) {
   NestedStructKeyInStructTest();
   FixedSizedStructArrayKeyInStructTest();
   EmbeddedSchemaAccess();
+  Offset64Tests();
   return 0;
 }
 }  // namespace
diff --git a/tests/test_builder.cpp b/tests/test_builder.cpp
index 047a380c..3b0eaa04 100644
--- a/tests/test_builder.cpp
+++ b/tests/test_builder.cpp
@@ -1,20 +1,22 @@
 #include "test_builder.h"
 
+#include "flatbuffers/flatbuffer_builder.h"
 #include "flatbuffers/stl_emulation.h"
 #include "monster_test_generated.h"
 
 using namespace MyGame::Example;
+using namespace flatbuffers;
 
-struct OwnedAllocator : public flatbuffers::DefaultAllocator {};
+struct OwnedAllocator : public DefaultAllocator {};
 
-class TestHeapBuilder : public flatbuffers::FlatBufferBuilder {
+class TestHeapBuilder : public FlatBufferBuilder {
  private:
   TestHeapBuilder(const TestHeapBuilder &);
   TestHeapBuilder &operator=(const TestHeapBuilder &);
 
  public:
   TestHeapBuilder()
-      : flatbuffers::FlatBufferBuilder(2048, new OwnedAllocator(), true) {}
+      : FlatBufferBuilder(2048, new OwnedAllocator(), true) {}
 
   TestHeapBuilder(TestHeapBuilder &&other)
       : FlatBufferBuilder(std::move(other)) {}
@@ -31,14 +33,14 @@ struct AllocatorMember {
 };
 
 struct GrpcLikeMessageBuilder : private AllocatorMember,
-                                public flatbuffers::FlatBufferBuilder {
+                                public FlatBufferBuilder {
  private:
   GrpcLikeMessageBuilder(const GrpcLikeMessageBuilder &);
   GrpcLikeMessageBuilder &operator=(const GrpcLikeMessageBuilder &);
 
  public:
   GrpcLikeMessageBuilder()
-      : flatbuffers::FlatBufferBuilder(1024, &member_allocator_, false) {}
+      : FlatBufferBuilder(1024, &member_allocator_, false) {}
 
   GrpcLikeMessageBuilder(GrpcLikeMessageBuilder &&other)
       : FlatBufferBuilder(1024, &member_allocator_, false) {
diff --git a/tests/test_builder.h b/tests/test_builder.h
index 75338b04..8a214bab 100644
--- a/tests/test_builder.h
+++ b/tests/test_builder.h
@@ -17,10 +17,6 @@ class MessageBuilder;
 }
 }  // namespace flatbuffers
 
-template<class T, class U> struct is_same { static const bool value = false; };
-
-template<class T> struct is_same<T, T> { static const bool value = true; };
-
 inline std::string m1_name() { return "Cyberdemon"; }
 inline std::string m2_name() { return "Imp"; }
 inline MyGame::Example::Color m1_color() {
@@ -166,7 +162,7 @@ struct BuilderTests {
   }
 
   static void builder_swap_before_finish_test(
-      bool run = is_same<DestBuilder, SrcBuilder>::value) {
+      bool run = std::is_same<DestBuilder, SrcBuilder>::value) {
     /// Swap is allowed only when lhs and rhs are the same concrete type.
     if (run) {
       SrcBuilder src;
@@ -186,7 +182,7 @@ struct BuilderTests {
   }
 
   static void builder_swap_after_finish_test(
-      bool run = is_same<DestBuilder, SrcBuilder>::value) {
+      bool run = std::is_same<DestBuilder, SrcBuilder>::value) {
     /// Swap is allowed only when lhs and rhs are the same concrete type.
     if (run) {
       SrcBuilder src;