Add new c++ helpers to ease usage of size prefixed FlatBuffers (#4626)

It was missing some helpers when we choose to use
size prefixed FlatBuffers.

* Add general helper : GetPrefixedSize
* Add generated helpers :
 * GetSizePrefixedXXX
 * VerfifySizePrefixedXXXBuffer
 * FinishSizePrefixedXXXBuffer

1 files changed, 15 insertions, 0 deletions

diff --git a/samples/monster_generated.h b/samples/monster_generated.h
index 32d44d00..00c0595e 100644
--- a/samples/monster_generated.h
+++ b/samples/monster_generated.h
@@ -727,6 +727,10 @@ inline const MyGame::Sample::Monster *GetMonster(const void *buf) {
   return flatbuffers::GetRoot<MyGame::Sample::Monster>(buf);
 }
 
+inline const MyGame::Sample::Monster *GetSizePrefixedMonster(const void *buf) {
+  return flatbuffers::GetSizePrefixedRoot<MyGame::Sample::Monster>(buf);
+}
+
 inline Monster *GetMutableMonster(void *buf) {
   return flatbuffers::GetMutableRoot<Monster>(buf);
 }
@@ -736,12 +740,23 @@ inline bool VerifyMonsterBuffer(
   return verifier.VerifyBuffer<MyGame::Sample::Monster>(nullptr);
 }
 
+inline bool VerifySizePrefixedMonsterBuffer(
+    flatbuffers::Verifier &verifier) {
+  return verifier.VerifySizePrefixedBuffer<MyGame::Sample::Monster>(nullptr);
+}
+
 inline void FinishMonsterBuffer(
     flatbuffers::FlatBufferBuilder &fbb,
     flatbuffers::Offset<MyGame::Sample::Monster> root) {
   fbb.Finish(root);
 }
 
+inline void FinishSizePrefixedMonsterBuffer(
+    flatbuffers::FlatBufferBuilder &fbb,
+    flatbuffers::Offset<MyGame::Sample::Monster> root) {
+  fbb.FinishSizePrefixed(root);
+}
+
 inline flatbuffers::unique_ptr<MonsterT> UnPackMonster(
     const void *buf,
     const flatbuffers::resolver_function_t *res = nullptr) {