Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 3488 insertions, 0 deletions

diff --git a/src/arrow/cpp/thirdparty/flatbuffers/include/flatbuffers/base.h b/src/arrow/cpp/thirdparty/flatbuffers/include/flatbuffers/base.h
new file mode 100644
index 000000000..955738067
--- /dev/null
+++ b/src/arrow/cpp/thirdparty/flatbuffers/include/flatbuffers/base.h
@@ -0,0 +1,398 @@
+#ifndef FLATBUFFERS_BASE_H_
+#define FLATBUFFERS_BASE_H_
+
+// clang-format off
+
+// If activate should be declared and included first.
+#if defined(FLATBUFFERS_MEMORY_LEAK_TRACKING) && \
+    defined(_MSC_VER) && defined(_DEBUG)
+  // The _CRTDBG_MAP_ALLOC inside <crtdbg.h> will replace
+  // calloc/free (etc) to its debug version using #define directives.
+  #define _CRTDBG_MAP_ALLOC
+  #include <stdlib.h>
+  #include <crtdbg.h>
+  // Replace operator new by trace-enabled version.
+  #define DEBUG_NEW new(_NORMAL_BLOCK, __FILE__, __LINE__)
+  #define new DEBUG_NEW
+#endif
+
+#if !defined(FLATBUFFERS_ASSERT)
+#include <assert.h>
+#define FLATBUFFERS_ASSERT assert
+#elif defined(FLATBUFFERS_ASSERT_INCLUDE)
+// Include file with forward declaration
+#include FLATBUFFERS_ASSERT_INCLUDE
+#endif
+
+#ifndef ARDUINO
+#include <cstdint>
+#endif
+
+#include <cstddef>
+#include <cstdlib>
+#include <cstring>
+
+#if defined(ARDUINO) && !defined(ARDUINOSTL_M_H)
+  #include <utility.h>
+#else
+  #include <utility>
+#endif
+
+#include <string>
+#include <type_traits>
+#include <vector>
+#include <set>
+#include <algorithm>
+#include <iterator>
+#include <memory>
+
+#ifdef _STLPORT_VERSION
+  #define FLATBUFFERS_CPP98_STL
+#endif
+#ifndef FLATBUFFERS_CPP98_STL
+  #include <functional>
+#endif
+
+#include "flatbuffers/stl_emulation.h"
+
+#if defined(__ICCARM__)
+#include <intrinsics.h>
+#endif
+
+// Note the __clang__ check is needed, because clang presents itself
+// as an older GNUC compiler (4.2).
+// Clang 3.3 and later implement all of the ISO C++ 2011 standard.
+// Clang 3.4 and later implement all of the ISO C++ 2014 standard.
+// http://clang.llvm.org/cxx_status.html
+
+// Note the MSVC value '__cplusplus' may be incorrect:
+// The '__cplusplus' predefined macro in the MSVC stuck at the value 199711L,
+// indicating (erroneously!) that the compiler conformed to the C++98 Standard.
+// This value should be correct starting from MSVC2017-15.7-Preview-3.
+// The '__cplusplus' will be valid only if MSVC2017-15.7-P3 and the `/Zc:__cplusplus` switch is set.
+// Workaround (for details see MSDN):
+// Use the _MSC_VER and _MSVC_LANG definition instead of the __cplusplus  for compatibility.
+// The _MSVC_LANG macro reports the Standard version regardless of the '/Zc:__cplusplus' switch.
+
+#if defined(__GNUC__) && !defined(__clang__)
+  #define FLATBUFFERS_GCC (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__)
+#else
+  #define FLATBUFFERS_GCC 0
+#endif
+
+#if defined(__clang__)
+  #define FLATBUFFERS_CLANG (__clang_major__ * 10000 + __clang_minor__ * 100 + __clang_patchlevel__)
+#else
+  #define FLATBUFFERS_CLANG 0
+#endif
+
+/// @cond FLATBUFFERS_INTERNAL
+#if __cplusplus <= 199711L && \
+    (!defined(_MSC_VER) || _MSC_VER < 1600) && \
+    (!defined(__GNUC__) || \
+      (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__ < 40400))
+  #error A C++11 compatible compiler with support for the auto typing is \
+         required for FlatBuffers.
+  #error __cplusplus _MSC_VER __GNUC__  __GNUC_MINOR__  __GNUC_PATCHLEVEL__
+#endif
+
+#if !defined(__clang__) && \
+    defined(__GNUC__) && \
+    (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__ < 40600)
+  // Backwards compatibility for g++ 4.4, and 4.5 which don't have the nullptr
+  // and constexpr keywords. Note the __clang__ check is needed, because clang
+  // presents itself as an older GNUC compiler.
+  #ifndef nullptr_t
+    const class nullptr_t {
+    public:
+      template<class T> inline operator T*() const { return 0; }
+    private:
+      void operator&() const;
+    } nullptr = {};
+  #endif
+  #ifndef constexpr
+    #define constexpr const
+  #endif
+#endif
+
+// The wire format uses a little endian encoding (since that's efficient for
+// the common platforms).
+#if defined(__s390x__)
+  #define FLATBUFFERS_LITTLEENDIAN 0
+#endif // __s390x__
+#if !defined(FLATBUFFERS_LITTLEENDIAN)
+  #if defined(__GNUC__) || defined(__clang__) || defined(__ICCARM__)
+    #if (defined(__BIG_ENDIAN__) || \
+         (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))
+      #define FLATBUFFERS_LITTLEENDIAN 0
+    #else
+      #define FLATBUFFERS_LITTLEENDIAN 1
+    #endif // __BIG_ENDIAN__
+  #elif defined(_MSC_VER)
+    #if defined(_M_PPC)
+      #define FLATBUFFERS_LITTLEENDIAN 0
+    #else
+      #define FLATBUFFERS_LITTLEENDIAN 1
+    #endif
+  #else
+    #error Unable to determine endianness, define FLATBUFFERS_LITTLEENDIAN.
+  #endif
+#endif // !defined(FLATBUFFERS_LITTLEENDIAN)
+
+#define FLATBUFFERS_VERSION_MAJOR 1
+#define FLATBUFFERS_VERSION_MINOR 12
+#define FLATBUFFERS_VERSION_REVISION 0
+#define FLATBUFFERS_STRING_EXPAND(X) #X
+#define FLATBUFFERS_STRING(X) FLATBUFFERS_STRING_EXPAND(X)
+namespace flatbuffers {
+  // Returns version as string  "MAJOR.MINOR.REVISION".
+  const char* FLATBUFFERS_VERSION();
+}
+
+#if (!defined(_MSC_VER) || _MSC_VER > 1600) && \
+    (!defined(__GNUC__) || (__GNUC__ * 100 + __GNUC_MINOR__ >= 407)) || \
+    defined(__clang__)
+  #define FLATBUFFERS_FINAL_CLASS final
+  #define FLATBUFFERS_OVERRIDE override
+  #define FLATBUFFERS_VTABLE_UNDERLYING_TYPE : flatbuffers::voffset_t
+#else
+  #define FLATBUFFERS_FINAL_CLASS
+  #define FLATBUFFERS_OVERRIDE
+  #define FLATBUFFERS_VTABLE_UNDERLYING_TYPE
+#endif
+
+#if (!defined(_MSC_VER) || _MSC_VER >= 1900) && \
+    (!defined(__GNUC__) || (__GNUC__ * 100 + __GNUC_MINOR__ >= 406)) || \
+    (defined(__cpp_constexpr) && __cpp_constexpr >= 200704)
+  #define FLATBUFFERS_CONSTEXPR constexpr
+#else
+  #define FLATBUFFERS_CONSTEXPR const
+#endif
+
+#if (defined(__cplusplus) && __cplusplus >= 201402L) || \
+    (defined(__cpp_constexpr) && __cpp_constexpr >= 201304)
+  #define FLATBUFFERS_CONSTEXPR_CPP14 FLATBUFFERS_CONSTEXPR
+#else
+  #define FLATBUFFERS_CONSTEXPR_CPP14
+#endif
+
+#if (defined(__GXX_EXPERIMENTAL_CXX0X__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 406)) || \
+    (defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 190023026)) || \
+    defined(__clang__)
+  #define FLATBUFFERS_NOEXCEPT noexcept
+#else
+  #define FLATBUFFERS_NOEXCEPT
+#endif
+
+// NOTE: the FLATBUFFERS_DELETE_FUNC macro may change the access mode to
+// private, so be sure to put it at the end or reset access mode explicitly.
+#if (!defined(_MSC_VER) || _MSC_FULL_VER >= 180020827) && \
+    (!defined(__GNUC__) || (__GNUC__ * 100 + __GNUC_MINOR__ >= 404)) || \
+    defined(__clang__)
+  #define FLATBUFFERS_DELETE_FUNC(func) func = delete;
+#else
+  #define FLATBUFFERS_DELETE_FUNC(func) private: func;
+#endif
+
+#ifndef FLATBUFFERS_HAS_STRING_VIEW
+  // Only provide flatbuffers::string_view if __has_include can be used
+  // to detect a header that provides an implementation
+  #if defined(__has_include)
+    // Check for std::string_view (in c++17)
+    #if __has_include(<string_view>) && (__cplusplus >= 201606 || (defined(_HAS_CXX17) && _HAS_CXX17))
+      #include <string_view>
+      namespace flatbuffers {
+        typedef std::string_view string_view;
+      }
+      #define FLATBUFFERS_HAS_STRING_VIEW 1
+    // Check for std::experimental::string_view (in c++14, compiler-dependent)
+    #elif __has_include(<experimental/string_view>) && (__cplusplus >= 201411)
+      #include <experimental/string_view>
+      namespace flatbuffers {
+        typedef std::experimental::string_view string_view;
+      }
+      #define FLATBUFFERS_HAS_STRING_VIEW 1
+    // Check for absl::string_view
+    #elif __has_include("absl/strings/string_view.h")
+      #include "absl/strings/string_view.h"
+      namespace flatbuffers {
+        typedef absl::string_view string_view;
+      }
+      #define FLATBUFFERS_HAS_STRING_VIEW 1
+    #endif
+  #endif // __has_include
+#endif // !FLATBUFFERS_HAS_STRING_VIEW
+
+#ifndef FLATBUFFERS_HAS_NEW_STRTOD
+  // Modern (C++11) strtod and strtof functions are available for use.
+  // 1) nan/inf strings as argument of strtod;
+  // 2) hex-float  as argument of  strtod/strtof.
+  #if (defined(_MSC_VER) && _MSC_VER >= 1900) || \
+      (defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 409)) || \
+      (defined(__clang__))
+    #define FLATBUFFERS_HAS_NEW_STRTOD 1
+  #endif
+#endif // !FLATBUFFERS_HAS_NEW_STRTOD
+
+#ifndef FLATBUFFERS_LOCALE_INDEPENDENT
+  // Enable locale independent functions {strtof_l, strtod_l,strtoll_l, strtoull_l}.
+  // They are part of the POSIX-2008 but not part of the C/C++ standard.
+  // GCC/Clang have definition (_XOPEN_SOURCE>=700) if POSIX-2008.
+  #if ((defined(_MSC_VER) && _MSC_VER >= 1800)            || \
+       (defined(_XOPEN_SOURCE) && (_XOPEN_SOURCE>=700)))
+    #define FLATBUFFERS_LOCALE_INDEPENDENT 1
+  #else
+    #define FLATBUFFERS_LOCALE_INDEPENDENT 0
+  #endif
+#endif  // !FLATBUFFERS_LOCALE_INDEPENDENT
+
+// Suppress Undefined Behavior Sanitizer (recoverable only). Usage:
+// - __supress_ubsan__("undefined")
+// - __supress_ubsan__("signed-integer-overflow")
+#if defined(__clang__) && (__clang_major__ > 3 || (__clang_major__ == 3 && __clang_minor__ >=7))
+  #define __supress_ubsan__(type) __attribute__((no_sanitize(type)))
+#elif defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 409)
+  #define __supress_ubsan__(type) __attribute__((no_sanitize_undefined))
+#else
+  #define __supress_ubsan__(type)
+#endif
+
+// This is constexpr function used for checking compile-time constants.
+// Avoid `#pragma warning(disable: 4127) // C4127: expression is constant`.
+template<typename T> FLATBUFFERS_CONSTEXPR inline bool IsConstTrue(T t) {
+  return !!t;
+}
+
+// Enable C++ attribute [[]] if std:c++17 or higher.
+#if ((__cplusplus >= 201703L) \
+    || (defined(_MSVC_LANG) &&  (_MSVC_LANG >= 201703L)))
+  // All attributes unknown to an implementation are ignored without causing an error.
+  #define FLATBUFFERS_ATTRIBUTE(attr) [[attr]]
+
+  #define FLATBUFFERS_FALLTHROUGH() [[fallthrough]]
+#else
+  #define FLATBUFFERS_ATTRIBUTE(attr)
+
+  #if FLATBUFFERS_CLANG >= 30800
+    #define FLATBUFFERS_FALLTHROUGH() [[clang::fallthrough]]
+  #elif FLATBUFFERS_GCC >= 70300
+    #define FLATBUFFERS_FALLTHROUGH() [[gnu::fallthrough]]
+  #else
+    #define FLATBUFFERS_FALLTHROUGH()
+  #endif
+#endif
+
+/// @endcond
+
+/// @file
+namespace flatbuffers {
+
+/// @cond FLATBUFFERS_INTERNAL
+// Our default offset / size type, 32bit on purpose on 64bit systems.
+// Also, using a consistent offset type maintains compatibility of serialized
+// offset values between 32bit and 64bit systems.
+typedef uint32_t uoffset_t;
+
+// Signed offsets for references that can go in both directions.
+typedef int32_t soffset_t;
+
+// Offset/index used in v-tables, can be changed to uint8_t in
+// format forks to save a bit of space if desired.
+typedef uint16_t voffset_t;
+
+typedef uintmax_t largest_scalar_t;
+
+// In 32bits, this evaluates to 2GB - 1
+#define FLATBUFFERS_MAX_BUFFER_SIZE ((1ULL << (sizeof(::flatbuffers::soffset_t) * 8 - 1)) - 1)
+
+// We support aligning the contents of buffers up to this size.
+#define FLATBUFFERS_MAX_ALIGNMENT 16
+
+#if defined(_MSC_VER)
+  #pragma warning(push)
+  #pragma warning(disable: 4127) // C4127: conditional expression is constant
+#endif
+
+template<typename T> T EndianSwap(T t) {
+  #if defined(_MSC_VER)
+    #define FLATBUFFERS_BYTESWAP16 _byteswap_ushort
+    #define FLATBUFFERS_BYTESWAP32 _byteswap_ulong
+    #define FLATBUFFERS_BYTESWAP64 _byteswap_uint64
+  #elif defined(__ICCARM__)
+    #define FLATBUFFERS_BYTESWAP16 __REV16
+    #define FLATBUFFERS_BYTESWAP32 __REV
+    #define FLATBUFFERS_BYTESWAP64(x) \
+       ((__REV(static_cast<uint32_t>(x >> 32U))) | (static_cast<uint64_t>(__REV(static_cast<uint32_t>(x)))) << 32U)
+  #else
+    #if defined(__GNUC__) && __GNUC__ * 100 + __GNUC_MINOR__ < 408 && !defined(__clang__)
+      // __builtin_bswap16 was missing prior to GCC 4.8.
+      #define FLATBUFFERS_BYTESWAP16(x) \
+        static_cast<uint16_t>(__builtin_bswap32(static_cast<uint32_t>(x) << 16))
+    #else
+      #define FLATBUFFERS_BYTESWAP16 __builtin_bswap16
+    #endif
+    #define FLATBUFFERS_BYTESWAP32 __builtin_bswap32
+    #define FLATBUFFERS_BYTESWAP64 __builtin_bswap64
+  #endif
+  if (sizeof(T) == 1) {   // Compile-time if-then's.
+    return t;
+  } else if (sizeof(T) == 2) {
+    union { T t; uint16_t i; } u = { t };
+    u.i = FLATBUFFERS_BYTESWAP16(u.i);
+    return u.t;
+  } else if (sizeof(T) == 4) {
+    union { T t; uint32_t i; } u = { t };
+    u.i = FLATBUFFERS_BYTESWAP32(u.i);
+    return u.t;
+  } else if (sizeof(T) == 8) {
+    union { T t; uint64_t i; } u = { t };
+    u.i = FLATBUFFERS_BYTESWAP64(u.i);
+    return u.t;
+  } else {
+    FLATBUFFERS_ASSERT(0);
+    return t;
+  }
+}
+
+#if defined(_MSC_VER)
+  #pragma warning(pop)
+#endif
+
+
+template<typename T> T EndianScalar(T t) {
+  #if FLATBUFFERS_LITTLEENDIAN
+    return t;
+  #else
+    return EndianSwap(t);
+  #endif
+}
+
+template<typename T>
+// UBSAN: C++ aliasing type rules, see std::bit_cast<> for details.
+__supress_ubsan__("alignment")
+T ReadScalar(const void *p) {
+  return EndianScalar(*reinterpret_cast<const T *>(p));
+}
+
+template<typename T>
+// UBSAN: C++ aliasing type rules, see std::bit_cast<> for details.
+__supress_ubsan__("alignment")
+void WriteScalar(void *p, T t) {
+  *reinterpret_cast<T *>(p) = EndianScalar(t);
+}
+
+template<typename T> struct Offset;
+template<typename T> __supress_ubsan__("alignment") void WriteScalar(void *p, Offset<T> t) {
+  *reinterpret_cast<uoffset_t *>(p) = EndianScalar(t.o);
+}
+
+// Computes how many bytes you'd have to pad to be able to write an
+// "scalar_size" scalar if the buffer had grown to "buf_size" (downwards in
+// memory).
+__supress_ubsan__("unsigned-integer-overflow")
+inline size_t PaddingBytes(size_t buf_size, size_t scalar_size) {
+  return ((~buf_size) + 1) & (scalar_size - 1);
+}
+
+}  // namespace flatbuffers
+#endif  // FLATBUFFERS_BASE_H_
diff --git a/src/arrow/cpp/thirdparty/flatbuffers/include/flatbuffers/flatbuffers.h b/src/arrow/cpp/thirdparty/flatbuffers/include/flatbuffers/flatbuffers.h
new file mode 100644
index 000000000..c4dc5bcd0
--- /dev/null
+++ b/src/arrow/cpp/thirdparty/flatbuffers/include/flatbuffers/flatbuffers.h
@@ -0,0 +1,2783 @@
+/*
+ * Copyright 2014 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FLATBUFFERS_H_
+#define FLATBUFFERS_H_
+
+#include "flatbuffers/base.h"
+
+#if defined(FLATBUFFERS_NAN_DEFAULTS)
+#  include <cmath>
+#endif
+
+namespace flatbuffers {
+// Generic 'operator==' with conditional specialisations.
+// T e - new value of a scalar field.
+// T def - default of scalar (is known at compile-time).
+template<typename T> inline bool IsTheSameAs(T e, T def) { return e == def; }
+
+#if defined(FLATBUFFERS_NAN_DEFAULTS) && \
+    defined(FLATBUFFERS_HAS_NEW_STRTOD) && (FLATBUFFERS_HAS_NEW_STRTOD > 0)
+// Like `operator==(e, def)` with weak NaN if T=(float|double).
+template<typename T> inline bool IsFloatTheSameAs(T e, T def) {
+  return (e == def) || ((def != def) && (e != e));
+}
+template<> inline bool IsTheSameAs<float>(float e, float def) {
+  return IsFloatTheSameAs(e, def);
+}
+template<> inline bool IsTheSameAs<double>(double e, double def) {
+  return IsFloatTheSameAs(e, def);
+}
+#endif
+
+// Check 'v' is out of closed range [low; high].
+// Workaround for GCC warning [-Werror=type-limits]:
+// comparison is always true due to limited range of data type.
+template<typename T>
+inline bool IsOutRange(const T &v, const T &low, const T &high) {
+  return (v < low) || (high < v);
+}
+
+// Check 'v' is in closed range [low; high].
+template<typename T>
+inline bool IsInRange(const T &v, const T &low, const T &high) {
+  return !IsOutRange(v, low, high);
+}
+
+// Wrapper for uoffset_t to allow safe template specialization.
+// Value is allowed to be 0 to indicate a null object (see e.g. AddOffset).
+template<typename T> struct Offset {
+  uoffset_t o;
+  Offset() : o(0) {}
+  Offset(uoffset_t _o) : o(_o) {}
+  Offset<void> Union() const { return Offset<void>(o); }
+  bool IsNull() const { return !o; }
+};
+
+inline void EndianCheck() {
+  int endiantest = 1;
+  // If this fails, see FLATBUFFERS_LITTLEENDIAN above.
+  FLATBUFFERS_ASSERT(*reinterpret_cast<char *>(&endiantest) ==
+                     FLATBUFFERS_LITTLEENDIAN);
+  (void)endiantest;
+}
+
+template<typename T> FLATBUFFERS_CONSTEXPR size_t AlignOf() {
+  // clang-format off
+  #ifdef _MSC_VER
+    return __alignof(T);
+  #else
+    #ifndef alignof
+      return __alignof__(T);
+    #else
+      return alignof(T);
+    #endif
+  #endif
+  // clang-format on
+}
+
+// When we read serialized data from memory, in the case of most scalars,
+// we want to just read T, but in the case of Offset, we want to actually
+// perform the indirection and return a pointer.
+// The template specialization below does just that.
+// It is wrapped in a struct since function templates can't overload on the
+// return type like this.
+// The typedef is for the convenience of callers of this function
+// (avoiding the need for a trailing return decltype)
+template<typename T> struct IndirectHelper {
+  typedef T return_type;
+  typedef T mutable_return_type;
+  static const size_t element_stride = sizeof(T);
+  static return_type Read(const uint8_t *p, uoffset_t i) {
+    return EndianScalar((reinterpret_cast<const T *>(p))[i]);
+  }
+};
+template<typename T> struct IndirectHelper<Offset<T>> {
+  typedef const T *return_type;
+  typedef T *mutable_return_type;
+  static const size_t element_stride = sizeof(uoffset_t);
+  static return_type Read(const uint8_t *p, uoffset_t i) {
+    p += i * sizeof(uoffset_t);
+    return reinterpret_cast<return_type>(p + ReadScalar<uoffset_t>(p));
+  }
+};
+template<typename T> struct IndirectHelper<const T *> {
+  typedef const T *return_type;
+  typedef T *mutable_return_type;
+  static const size_t element_stride = sizeof(T);
+  static return_type Read(const uint8_t *p, uoffset_t i) {
+    return reinterpret_cast<const T *>(p + i * sizeof(T));
+  }
+};
+
+// An STL compatible iterator implementation for Vector below, effectively
+// calling Get() for every element.
+template<typename T, typename IT> struct VectorIterator {
+  typedef std::random_access_iterator_tag iterator_category;
+  typedef IT value_type;
+  typedef ptrdiff_t difference_type;
+  typedef IT *pointer;
+  typedef IT &reference;
+
+  VectorIterator(const uint8_t *data, uoffset_t i)
+      : data_(data + IndirectHelper<T>::element_stride * i) {}
+  VectorIterator(const VectorIterator &other) : data_(other.data_) {}
+  VectorIterator() : data_(nullptr) {}
+
+  VectorIterator &operator=(const VectorIterator &other) {
+    data_ = other.data_;
+    return *this;
+  }
+
+  // clang-format off
+  #if !defined(FLATBUFFERS_CPP98_STL)
+  VectorIterator &operator=(VectorIterator &&other) {
+    data_ = other.data_;
+    return *this;
+  }
+  #endif  // !defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+
+  bool operator==(const VectorIterator &other) const {
+    return data_ == other.data_;
+  }
+
+  bool operator<(const VectorIterator &other) const {
+    return data_ < other.data_;
+  }
+
+  bool operator!=(const VectorIterator &other) const {
+    return data_ != other.data_;
+  }
+
+  difference_type operator-(const VectorIterator &other) const {
+    return (data_ - other.data_) / IndirectHelper<T>::element_stride;
+  }
+
+  IT operator*() const { return IndirectHelper<T>::Read(data_, 0); }
+
+  IT operator->() const { return IndirectHelper<T>::Read(data_, 0); }
+
+  VectorIterator &operator++() {
+    data_ += IndirectHelper<T>::element_stride;
+    return *this;
+  }
+
+  VectorIterator operator++(int) {
+    VectorIterator temp(data_, 0);
+    data_ += IndirectHelper<T>::element_stride;
+    return temp;
+  }
+
+  VectorIterator operator+(const uoffset_t &offset) const {
+    return VectorIterator(data_ + offset * IndirectHelper<T>::element_stride,
+                          0);
+  }
+
+  VectorIterator &operator+=(const uoffset_t &offset) {
+    data_ += offset * IndirectHelper<T>::element_stride;
+    return *this;
+  }
+
+  VectorIterator &operator--() {
+    data_ -= IndirectHelper<T>::element_stride;
+    return *this;
+  }
+
+  VectorIterator operator--(int) {
+    VectorIterator temp(data_, 0);
+    data_ -= IndirectHelper<T>::element_stride;
+    return temp;
+  }
+
+  VectorIterator operator-(const uoffset_t &offset) const {
+    return VectorIterator(data_ - offset * IndirectHelper<T>::element_stride,
+                          0);
+  }
+
+  VectorIterator &operator-=(const uoffset_t &offset) {
+    data_ -= offset * IndirectHelper<T>::element_stride;
+    return *this;
+  }
+
+ private:
+  const uint8_t *data_;
+};
+
+template<typename Iterator>
+struct VectorReverseIterator : public std::reverse_iterator<Iterator> {
+  explicit VectorReverseIterator(Iterator iter)
+      : std::reverse_iterator<Iterator>(iter) {}
+
+  typename Iterator::value_type operator*() const {
+    return *(std::reverse_iterator<Iterator>::current);
+  }
+
+  typename Iterator::value_type operator->() const {
+    return *(std::reverse_iterator<Iterator>::current);
+  }
+};
+
+struct String;
+
+// This is used as a helper type for accessing vectors.
+// Vector::data() assumes the vector elements start after the length field.
+template<typename T> class Vector {
+ public:
+  typedef VectorIterator<T, typename IndirectHelper<T>::mutable_return_type>
+      iterator;
+  typedef VectorIterator<T, typename IndirectHelper<T>::return_type>
+      const_iterator;
+  typedef VectorReverseIterator<iterator> reverse_iterator;
+  typedef VectorReverseIterator<const_iterator> const_reverse_iterator;
+
+  uoffset_t size() const { return EndianScalar(length_); }
+
+  // Deprecated: use size(). Here for backwards compatibility.
+  FLATBUFFERS_ATTRIBUTE(deprecated("use size() instead"))
+  uoffset_t Length() const { return size(); }
+
+  typedef typename IndirectHelper<T>::return_type return_type;
+  typedef typename IndirectHelper<T>::mutable_return_type mutable_return_type;
+
+  return_type Get(uoffset_t i) const {
+    FLATBUFFERS_ASSERT(i < size());
+    return IndirectHelper<T>::Read(Data(), i);
+  }
+
+  return_type operator[](uoffset_t i) const { return Get(i); }
+
+  // If this is a Vector of enums, T will be its storage type, not the enum
+  // type. This function makes it convenient to retrieve value with enum
+  // type E.
+  template<typename E> E GetEnum(uoffset_t i) const {
+    return static_cast<E>(Get(i));
+  }
+
+  // If this a vector of unions, this does the cast for you. There's no check
+  // to make sure this is the right type!
+  template<typename U> const U *GetAs(uoffset_t i) const {
+    return reinterpret_cast<const U *>(Get(i));
+  }
+
+  // If this a vector of unions, this does the cast for you. There's no check
+  // to make sure this is actually a string!
+  const String *GetAsString(uoffset_t i) const {
+    return reinterpret_cast<const String *>(Get(i));
+  }
+
+  const void *GetStructFromOffset(size_t o) const {
+    return reinterpret_cast<const void *>(Data() + o);
+  }
+
+  iterator begin() { return iterator(Data(), 0); }
+  const_iterator begin() const { return const_iterator(Data(), 0); }
+
+  iterator end() { return iterator(Data(), size()); }
+  const_iterator end() const { return const_iterator(Data(), size()); }
+
+  reverse_iterator rbegin() { return reverse_iterator(end() - 1); }
+  const_reverse_iterator rbegin() const {
+    return const_reverse_iterator(end() - 1);
+  }
+
+  reverse_iterator rend() { return reverse_iterator(begin() - 1); }
+  const_reverse_iterator rend() const {
+    return const_reverse_iterator(begin() - 1);
+  }
+
+  const_iterator cbegin() const { return begin(); }
+
+  const_iterator cend() const { return end(); }
+
+  const_reverse_iterator crbegin() const { return rbegin(); }
+
+  const_reverse_iterator crend() const { return rend(); }
+
+  // Change elements if you have a non-const pointer to this object.
+  // Scalars only. See reflection.h, and the documentation.
+  void Mutate(uoffset_t i, const T &val) {
+    FLATBUFFERS_ASSERT(i < size());
+    WriteScalar(data() + i, val);
+  }
+
+  // Change an element of a vector of tables (or strings).
+  // "val" points to the new table/string, as you can obtain from
+  // e.g. reflection::AddFlatBuffer().
+  void MutateOffset(uoffset_t i, const uint8_t *val) {
+    FLATBUFFERS_ASSERT(i < size());
+    static_assert(sizeof(T) == sizeof(uoffset_t), "Unrelated types");
+    WriteScalar(data() + i,
+                static_cast<uoffset_t>(val - (Data() + i * sizeof(uoffset_t))));
+  }
+
+  // Get a mutable pointer to tables/strings inside this vector.
+  mutable_return_type GetMutableObject(uoffset_t i) const {
+    FLATBUFFERS_ASSERT(i < size());
+    return const_cast<mutable_return_type>(IndirectHelper<T>::Read(Data(), i));
+  }
+
+  // The raw data in little endian format. Use with care.
+  const uint8_t *Data() const {
+    return reinterpret_cast<const uint8_t *>(&length_ + 1);
+  }
+
+  uint8_t *Data() { return reinterpret_cast<uint8_t *>(&length_ + 1); }
+
+  // Similarly, but typed, much like std::vector::data
+  const T *data() const { return reinterpret_cast<const T *>(Data()); }
+  T *data() { return reinterpret_cast<T *>(Data()); }
+
+  template<typename K> return_type LookupByKey(K key) const {
+    void *search_result = std::bsearch(
+        &key, Data(), size(), IndirectHelper<T>::element_stride, KeyCompare<K>);
+
+    if (!search_result) {
+      return nullptr;  // Key not found.
+    }
+
+    const uint8_t *element = reinterpret_cast<const uint8_t *>(search_result);
+
+    return IndirectHelper<T>::Read(element, 0);
+  }
+
+ protected:
+  // This class is only used to access pre-existing data. Don't ever
+  // try to construct these manually.
+  Vector();
+
+  uoffset_t length_;
+
+ private:
+  // This class is a pointer. Copying will therefore create an invalid object.
+  // Private and unimplemented copy constructor.
+  Vector(const Vector &);
+  Vector &operator=(const Vector &);
+
+  template<typename K> static int KeyCompare(const void *ap, const void *bp) {
+    const K *key = reinterpret_cast<const K *>(ap);
+    const uint8_t *data = reinterpret_cast<const uint8_t *>(bp);
+    auto table = IndirectHelper<T>::Read(data, 0);
+
+    // std::bsearch compares with the operands transposed, so we negate the
+    // result here.
+    return -table->KeyCompareWithValue(*key);
+  }
+};
+
+// Represent a vector much like the template above, but in this case we
+// don't know what the element types are (used with reflection.h).
+class VectorOfAny {
+ public:
+  uoffset_t size() const { return EndianScalar(length_); }
+
+  const uint8_t *Data() const {
+    return reinterpret_cast<const uint8_t *>(&length_ + 1);
+  }
+  uint8_t *Data() { return reinterpret_cast<uint8_t *>(&length_ + 1); }
+
+ protected:
+  VectorOfAny();
+
+  uoffset_t length_;
+
+ private:
+  VectorOfAny(const VectorOfAny &);
+  VectorOfAny &operator=(const VectorOfAny &);
+};
+
+#ifndef FLATBUFFERS_CPP98_STL
+template<typename T, typename U>
+Vector<Offset<T>> *VectorCast(Vector<Offset<U>> *ptr) {
+  static_assert(std::is_base_of<T, U>::value, "Unrelated types");
+  return reinterpret_cast<Vector<Offset<T>> *>(ptr);
+}
+
+template<typename T, typename U>
+const Vector<Offset<T>> *VectorCast(const Vector<Offset<U>> *ptr) {
+  static_assert(std::is_base_of<T, U>::value, "Unrelated types");
+  return reinterpret_cast<const Vector<Offset<T>> *>(ptr);
+}
+#endif
+
+// Convenient helper function to get the length of any vector, regardless
+// of whether it is null or not (the field is not set).
+template<typename T> static inline size_t VectorLength(const Vector<T> *v) {
+  return v ? v->size() : 0;
+}
+
+// This is used as a helper type for accessing arrays.
+template<typename T, uint16_t length> class Array {
+  typedef
+      typename flatbuffers::integral_constant<bool,
+                                              flatbuffers::is_scalar<T>::value>
+          scalar_tag;
+  typedef
+      typename flatbuffers::conditional<scalar_tag::value, T, const T *>::type
+          IndirectHelperType;
+
+ public:
+  typedef typename IndirectHelper<IndirectHelperType>::return_type return_type;
+  typedef VectorIterator<T, return_type> const_iterator;
+  typedef VectorReverseIterator<const_iterator> const_reverse_iterator;
+
+  FLATBUFFERS_CONSTEXPR uint16_t size() const { return length; }
+
+  return_type Get(uoffset_t i) const {
+    FLATBUFFERS_ASSERT(i < size());
+    return IndirectHelper<IndirectHelperType>::Read(Data(), i);
+  }
+
+  return_type operator[](uoffset_t i) const { return Get(i); }
+
+  // If this is a Vector of enums, T will be its storage type, not the enum
+  // type. This function makes it convenient to retrieve value with enum
+  // type E.
+  template<typename E> E GetEnum(uoffset_t i) const {
+    return static_cast<E>(Get(i));
+  }
+
+  const_iterator begin() const { return const_iterator(Data(), 0); }
+  const_iterator end() const { return const_iterator(Data(), size()); }
+
+  const_reverse_iterator rbegin() const {
+    return const_reverse_iterator(end());
+  }
+  const_reverse_iterator rend() const { return const_reverse_iterator(end()); }
+
+  const_iterator cbegin() const { return begin(); }
+  const_iterator cend() const { return end(); }
+
+  const_reverse_iterator crbegin() const { return rbegin(); }
+  const_reverse_iterator crend() const { return rend(); }
+
+  // Get a mutable pointer to elements inside this array.
+  // This method used to mutate arrays of structs followed by a @p Mutate
+  // operation. For primitive types use @p Mutate directly.
+  // @warning Assignments and reads to/from the dereferenced pointer are not
+  //  automatically converted to the correct endianness.
+  typename flatbuffers::conditional<scalar_tag::value, void, T *>::type
+  GetMutablePointer(uoffset_t i) const {
+    FLATBUFFERS_ASSERT(i < size());
+    return const_cast<T *>(&data()[i]);
+  }
+
+  // Change elements if you have a non-const pointer to this object.
+  void Mutate(uoffset_t i, const T &val) { MutateImpl(scalar_tag(), i, val); }
+
+  // The raw data in little endian format. Use with care.
+  const uint8_t *Data() const { return data_; }
+
+  uint8_t *Data() { return data_; }
+
+  // Similarly, but typed, much like std::vector::data
+  const T *data() const { return reinterpret_cast<const T *>(Data()); }
+  T *data() { return reinterpret_cast<T *>(Data()); }
+
+ protected:
+  void MutateImpl(flatbuffers::integral_constant<bool, true>, uoffset_t i,
+                  const T &val) {
+    FLATBUFFERS_ASSERT(i < size());
+    WriteScalar(data() + i, val);
+  }
+
+  void MutateImpl(flatbuffers::integral_constant<bool, false>, uoffset_t i,
+                  const T &val) {
+    *(GetMutablePointer(i)) = val;
+  }
+
+  // This class is only used to access pre-existing data. Don't ever
+  // try to construct these manually.
+  // 'constexpr' allows us to use 'size()' at compile time.
+  // @note Must not use 'FLATBUFFERS_CONSTEXPR' here, as const is not allowed on
+  //  a constructor.
+#if defined(__cpp_constexpr)
+  constexpr Array();
+#else
+  Array();
+#endif
+
+  uint8_t data_[length * sizeof(T)];
+
+ private:
+  // This class is a pointer. Copying will therefore create an invalid object.
+  // Private and unimplemented copy constructor.
+  Array(const Array &);
+  Array &operator=(const Array &);
+};
+
+// Specialization for Array[struct] with access using Offset<void> pointer.
+// This specialization used by idl_gen_text.cpp.
+template<typename T, uint16_t length> class Array<Offset<T>, length> {
+  static_assert(flatbuffers::is_same<T, void>::value, "unexpected type T");
+
+ public:
+  typedef const void *return_type;
+
+  const uint8_t *Data() const { return data_; }
+
+  // Make idl_gen_text.cpp::PrintContainer happy.
+  return_type operator[](uoffset_t) const {
+    FLATBUFFERS_ASSERT(false);
+    return nullptr;
+  }
+
+ private:
+  // This class is only used to access pre-existing data.
+  Array();
+  Array(const Array &);
+  Array &operator=(const Array &);
+
+  uint8_t data_[1];
+};
+
+// Lexicographically compare two strings (possibly containing nulls), and
+// return true if the first is less than the second.
+static inline bool StringLessThan(const char *a_data, uoffset_t a_size,
+                                  const char *b_data, uoffset_t b_size) {
+  const auto cmp = memcmp(a_data, b_data, (std::min)(a_size, b_size));
+  return cmp == 0 ? a_size < b_size : cmp < 0;
+}
+
+struct String : public Vector<char> {
+  const char *c_str() const { return reinterpret_cast<const char *>(Data()); }
+  std::string str() const { return std::string(c_str(), size()); }
+
+  // clang-format off
+  #ifdef FLATBUFFERS_HAS_STRING_VIEW
+  flatbuffers::string_view string_view() const {
+    return flatbuffers::string_view(c_str(), size());
+  }
+  #endif // FLATBUFFERS_HAS_STRING_VIEW
+  // clang-format on
+
+  bool operator<(const String &o) const {
+    return StringLessThan(this->data(), this->size(), o.data(), o.size());
+  }
+};
+
+// Convenience function to get std::string from a String returning an empty
+// string on null pointer.
+static inline std::string GetString(const String *str) {
+  return str ? str->str() : "";
+}
+
+// Convenience function to get char* from a String returning an empty string on
+// null pointer.
+static inline const char *GetCstring(const String *str) {
+  return str ? str->c_str() : "";
+}
+
+// Allocator interface. This is flatbuffers-specific and meant only for
+// `vector_downward` usage.
+class Allocator {
+ public:
+  virtual ~Allocator() {}
+
+  // Allocate `size` bytes of memory.
+  virtual uint8_t *allocate(size_t size) = 0;
+
+  // Deallocate `size` bytes of memory at `p` allocated by this allocator.
+  virtual void deallocate(uint8_t *p, size_t size) = 0;
+
+  // Reallocate `new_size` bytes of memory, replacing the old region of size
+  // `old_size` at `p`. In contrast to a normal realloc, this grows downwards,
+  // and is intended specifcally for `vector_downward` use.
+  // `in_use_back` and `in_use_front` indicate how much of `old_size` is
+  // actually in use at each end, and needs to be copied.
+  virtual uint8_t *reallocate_downward(uint8_t *old_p, size_t old_size,
+                                       size_t new_size, size_t in_use_back,
+                                       size_t in_use_front) {
+    FLATBUFFERS_ASSERT(new_size > old_size);  // vector_downward only grows
+    uint8_t *new_p = allocate(new_size);
+    memcpy_downward(old_p, old_size, new_p, new_size, in_use_back,
+                    in_use_front);
+    deallocate(old_p, old_size);
+    return new_p;
+  }
+
+ protected:
+  // Called by `reallocate_downward` to copy memory from `old_p` of `old_size`
+  // to `new_p` of `new_size`. Only memory of size `in_use_front` and
+  // `in_use_back` will be copied from the front and back of the old memory
+  // allocation.
+  void memcpy_downward(uint8_t *old_p, size_t old_size, uint8_t *new_p,
+                       size_t new_size, size_t in_use_back,
+                       size_t in_use_front) {
+    memcpy(new_p + new_size - in_use_back, old_p + old_size - in_use_back,
+           in_use_back);
+    memcpy(new_p, old_p, in_use_front);
+  }
+};
+
+// DefaultAllocator uses new/delete to allocate memory regions
+class DefaultAllocator : public Allocator {
+ public:
+  uint8_t *allocate(size_t size) FLATBUFFERS_OVERRIDE {
+    return new uint8_t[size];
+  }
+
+  void deallocate(uint8_t *p, size_t) FLATBUFFERS_OVERRIDE { delete[] p; }
+
+  static void dealloc(void *p, size_t) { delete[] static_cast<uint8_t *>(p); }
+};
+
+// These functions allow for a null allocator to mean use the default allocator,
+// as used by DetachedBuffer and vector_downward below.
+// This is to avoid having a statically or dynamically allocated default
+// allocator, or having to move it between the classes that may own it.
+inline uint8_t *Allocate(Allocator *allocator, size_t size) {
+  return allocator ? allocator->allocate(size)
+                   : DefaultAllocator().allocate(size);
+}
+
+inline void Deallocate(Allocator *allocator, uint8_t *p, size_t size) {
+  if (allocator)
+    allocator->deallocate(p, size);
+  else
+    DefaultAllocator().deallocate(p, size);
+}
+
+inline uint8_t *ReallocateDownward(Allocator *allocator, uint8_t *old_p,
+                                   size_t old_size, size_t new_size,
+                                   size_t in_use_back, size_t in_use_front) {
+  return allocator ? allocator->reallocate_downward(old_p, old_size, new_size,
+                                                    in_use_back, in_use_front)
+                   : DefaultAllocator().reallocate_downward(
+                         old_p, old_size, new_size, in_use_back, in_use_front);
+}
+
+// DetachedBuffer is a finished flatbuffer memory region, detached from its
+// builder. The original memory region and allocator are also stored so that
+// the DetachedBuffer can manage the memory lifetime.
+class DetachedBuffer {
+ public:
+  DetachedBuffer()
+      : allocator_(nullptr),
+        own_allocator_(false),
+        buf_(nullptr),
+        reserved_(0),
+        cur_(nullptr),
+        size_(0) {}
+
+  DetachedBuffer(Allocator *allocator, bool own_allocator, uint8_t *buf,
+                 size_t reserved, uint8_t *cur, size_t sz)
+      : allocator_(allocator),
+        own_allocator_(own_allocator),
+        buf_(buf),
+        reserved_(reserved),
+        cur_(cur),
+        size_(sz) {}
+
+  // clang-format off
+  #if !defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+  DetachedBuffer(DetachedBuffer &&other)
+      : allocator_(other.allocator_),
+        own_allocator_(other.own_allocator_),
+        buf_(other.buf_),
+        reserved_(other.reserved_),
+        cur_(other.cur_),
+        size_(other.size_) {
+    other.reset();
+  }
+  // clang-format off
+  #endif  // !defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+
+  // clang-format off
+  #if !defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+  DetachedBuffer &operator=(DetachedBuffer &&other) {
+    if (this == &other) return *this;
+
+    destroy();
+
+    allocator_ = other.allocator_;
+    own_allocator_ = other.own_allocator_;
+    buf_ = other.buf_;
+    reserved_ = other.reserved_;
+    cur_ = other.cur_;
+    size_ = other.size_;
+
+    other.reset();
+
+    return *this;
+  }
+  // clang-format off
+  #endif  // !defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+
+  ~DetachedBuffer() { destroy(); }
+
+  const uint8_t *data() const { return cur_; }
+
+  uint8_t *data() { return cur_; }
+
+  size_t size() const { return size_; }
+
+  // clang-format off
+  #if 0  // disabled for now due to the ordering of classes in this header
+  template <class T>
+  bool Verify() const {
+    Verifier verifier(data(), size());
+    return verifier.Verify<T>(nullptr);
+  }
+
+  template <class T>
+  const T* GetRoot() const {
+    return flatbuffers::GetRoot<T>(data());
+  }
+
+  template <class T>
+  T* GetRoot() {
+    return flatbuffers::GetRoot<T>(data());
+  }
+  #endif
+  // clang-format on
+
+  // clang-format off
+  #if !defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+  // These may change access mode, leave these at end of public section
+  FLATBUFFERS_DELETE_FUNC(DetachedBuffer(const DetachedBuffer &other))
+  FLATBUFFERS_DELETE_FUNC(
+      DetachedBuffer &operator=(const DetachedBuffer &other))
+  // clang-format off
+  #endif  // !defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+
+ protected:
+  Allocator *allocator_;
+  bool own_allocator_;
+  uint8_t *buf_;
+  size_t reserved_;
+  uint8_t *cur_;
+  size_t size_;
+
+  inline void destroy() {
+    if (buf_) Deallocate(allocator_, buf_, reserved_);
+    if (own_allocator_ && allocator_) { delete allocator_; }
+    reset();
+  }
+
+  inline void reset() {
+    allocator_ = nullptr;
+    own_allocator_ = false;
+    buf_ = nullptr;
+    reserved_ = 0;
+    cur_ = nullptr;
+    size_ = 0;
+  }
+};
+
+// This is a minimal replication of std::vector<uint8_t> functionality,
+// except growing from higher to lower addresses. i.e push_back() inserts data
+// in the lowest address in the vector.
+// Since this vector leaves the lower part unused, we support a "scratch-pad"
+// that can be stored there for temporary data, to share the allocated space.
+// Essentially, this supports 2 std::vectors in a single buffer.
+class vector_downward {
+ public:
+  explicit vector_downward(size_t initial_size, Allocator *allocator,
+                           bool own_allocator, size_t buffer_minalign)
+      : allocator_(allocator),
+        own_allocator_(own_allocator),
+        initial_size_(initial_size),
+        buffer_minalign_(buffer_minalign),
+        reserved_(0),
+        buf_(nullptr),
+        cur_(nullptr),
+        scratch_(nullptr) {}
+
+  // clang-format off
+  #if !defined(FLATBUFFERS_CPP98_STL)
+  vector_downward(vector_downward &&other)
+  #else
+  vector_downward(vector_downward &other)
+  #endif  // defined(FLATBUFFERS_CPP98_STL)
+      // clang-format on
+      : allocator_(other.allocator_),
+        own_allocator_(other.own_allocator_),
+        initial_size_(other.initial_size_),
+        buffer_minalign_(other.buffer_minalign_),
+        reserved_(other.reserved_),
+        buf_(other.buf_),
+        cur_(other.cur_),
+        scratch_(other.scratch_) {
+    // No change in other.allocator_
+    // No change in other.initial_size_
+    // No change in other.buffer_minalign_
+    other.own_allocator_ = false;
+    other.reserved_ = 0;
+    other.buf_ = nullptr;
+    other.cur_ = nullptr;
+    other.scratch_ = nullptr;
+  }
+
+  // clang-format off
+  #if !defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+  vector_downward &operator=(vector_downward &&other) {
+    // Move construct a temporary and swap idiom
+    vector_downward temp(std::move(other));
+    swap(temp);
+    return *this;
+  }
+  // clang-format off
+  #endif  // defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+
+  ~vector_downward() {
+    clear_buffer();
+    clear_allocator();
+  }
+
+  void reset() {
+    clear_buffer();
+    clear();
+  }
+
+  void clear() {
+    if (buf_) {
+      cur_ = buf_ + reserved_;
+    } else {
+      reserved_ = 0;
+      cur_ = nullptr;
+    }
+    clear_scratch();
+  }
+
+  void clear_scratch() { scratch_ = buf_; }
+
+  void clear_allocator() {
+    if (own_allocator_ && allocator_) { delete allocator_; }
+    allocator_ = nullptr;
+    own_allocator_ = false;
+  }
+
+  void clear_buffer() {
+    if (buf_) Deallocate(allocator_, buf_, reserved_);
+    buf_ = nullptr;
+  }
+
+  // Relinquish the pointer to the caller.
+  uint8_t *release_raw(size_t &allocated_bytes, size_t &offset) {
+    auto *buf = buf_;
+    allocated_bytes = reserved_;
+    offset = static_cast<size_t>(cur_ - buf_);
+
+    // release_raw only relinquishes the buffer ownership.
+    // Does not deallocate or reset the allocator. Destructor will do that.
+    buf_ = nullptr;
+    clear();
+    return buf;
+  }
+
+  // Relinquish the pointer to the caller.
+  DetachedBuffer release() {
+    // allocator ownership (if any) is transferred to DetachedBuffer.
+    DetachedBuffer fb(allocator_, own_allocator_, buf_, reserved_, cur_,
+                      size());
+    if (own_allocator_) {
+      allocator_ = nullptr;
+      own_allocator_ = false;
+    }
+    buf_ = nullptr;
+    clear();
+    return fb;
+  }
+
+  size_t ensure_space(size_t len) {
+    FLATBUFFERS_ASSERT(cur_ >= scratch_ && scratch_ >= buf_);
+    if (len > static_cast<size_t>(cur_ - scratch_)) { reallocate(len); }
+    // Beyond this, signed offsets may not have enough range:
+    // (FlatBuffers > 2GB not supported).
+    FLATBUFFERS_ASSERT(size() < FLATBUFFERS_MAX_BUFFER_SIZE);
+    return len;
+  }
+
+  inline uint8_t *make_space(size_t len) {
+    size_t space = ensure_space(len);
+    cur_ -= space;
+    return cur_;
+  }
+
+  // Returns nullptr if using the DefaultAllocator.
+  Allocator *get_custom_allocator() { return allocator_; }
+
+  uoffset_t size() const {
+    return static_cast<uoffset_t>(reserved_ - (cur_ - buf_));
+  }
+
+  uoffset_t scratch_size() const {
+    return static_cast<uoffset_t>(scratch_ - buf_);
+  }
+
+  size_t capacity() const { return reserved_; }
+
+  uint8_t *data() const {
+    FLATBUFFERS_ASSERT(cur_);
+    return cur_;
+  }
+
+  uint8_t *scratch_data() const {
+    FLATBUFFERS_ASSERT(buf_);
+    return buf_;
+  }
+
+  uint8_t *scratch_end() const {
+    FLATBUFFERS_ASSERT(scratch_);
+    return scratch_;
+  }
+
+  uint8_t *data_at(size_t offset) const { return buf_ + reserved_ - offset; }
+
+  void push(const uint8_t *bytes, size_t num) {
+    if (num > 0) { memcpy(make_space(num), bytes, num); }
+  }
+
+  // Specialized version of push() that avoids memcpy call for small data.
+  template<typename T> void push_small(const T &little_endian_t) {
+    make_space(sizeof(T));
+    *reinterpret_cast<T *>(cur_) = little_endian_t;
+  }
+
+  template<typename T> void scratch_push_small(const T &t) {
+    ensure_space(sizeof(T));
+    *reinterpret_cast<T *>(scratch_) = t;
+    scratch_ += sizeof(T);
+  }
+
+  // fill() is most frequently called with small byte counts (<= 4),
+  // which is why we're using loops rather than calling memset.
+  void fill(size_t zero_pad_bytes) {
+    make_space(zero_pad_bytes);
+    for (size_t i = 0; i < zero_pad_bytes; i++) cur_[i] = 0;
+  }
+
+  // Version for when we know the size is larger.
+  // Precondition: zero_pad_bytes > 0
+  void fill_big(size_t zero_pad_bytes) {
+    memset(make_space(zero_pad_bytes), 0, zero_pad_bytes);
+  }
+
+  void pop(size_t bytes_to_remove) { cur_ += bytes_to_remove; }
+  void scratch_pop(size_t bytes_to_remove) { scratch_ -= bytes_to_remove; }
+
+  void swap(vector_downward &other) {
+    using std::swap;
+    swap(allocator_, other.allocator_);
+    swap(own_allocator_, other.own_allocator_);
+    swap(initial_size_, other.initial_size_);
+    swap(buffer_minalign_, other.buffer_minalign_);
+    swap(reserved_, other.reserved_);
+    swap(buf_, other.buf_);
+    swap(cur_, other.cur_);
+    swap(scratch_, other.scratch_);
+  }
+
+  void swap_allocator(vector_downward &other) {
+    using std::swap;
+    swap(allocator_, other.allocator_);
+    swap(own_allocator_, other.own_allocator_);
+  }
+
+ private:
+  // You shouldn't really be copying instances of this class.
+  FLATBUFFERS_DELETE_FUNC(vector_downward(const vector_downward &))
+  FLATBUFFERS_DELETE_FUNC(vector_downward &operator=(const vector_downward &))
+
+  Allocator *allocator_;
+  bool own_allocator_;
+  size_t initial_size_;
+  size_t buffer_minalign_;
+  size_t reserved_;
+  uint8_t *buf_;
+  uint8_t *cur_;  // Points at location between empty (below) and used (above).
+  uint8_t *scratch_;  // Points to the end of the scratchpad in use.
+
+  void reallocate(size_t len) {
+    auto old_reserved = reserved_;
+    auto old_size = size();
+    auto old_scratch_size = scratch_size();
+    reserved_ +=
+        (std::max)(len, old_reserved ? old_reserved / 2 : initial_size_);
+    reserved_ = (reserved_ + buffer_minalign_ - 1) & ~(buffer_minalign_ - 1);
+    if (buf_) {
+      buf_ = ReallocateDownward(allocator_, buf_, old_reserved, reserved_,
+                                old_size, old_scratch_size);
+    } else {
+      buf_ = Allocate(allocator_, reserved_);
+    }
+    cur_ = buf_ + reserved_ - old_size;
+    scratch_ = buf_ + old_scratch_size;
+  }
+};
+
+// Converts a Field ID to a virtual table offset.
+inline voffset_t FieldIndexToOffset(voffset_t field_id) {
+  // Should correspond to what EndTable() below builds up.
+  const int fixed_fields = 2;  // Vtable size and Object Size.
+  return static_cast<voffset_t>((field_id + fixed_fields) * sizeof(voffset_t));
+}
+
+template<typename T, typename Alloc>
+const T *data(const std::vector<T, Alloc> &v) {
+  // Eventually the returned pointer gets passed down to memcpy, so
+  // we need it to be non-null to avoid undefined behavior.
+  static uint8_t t;
+  return v.empty() ? reinterpret_cast<const T *>(&t) : &v.front();
+}
+template<typename T, typename Alloc> T *data(std::vector<T, Alloc> &v) {
+  // Eventually the returned pointer gets passed down to memcpy, so
+  // we need it to be non-null to avoid undefined behavior.
+  static uint8_t t;
+  return v.empty() ? reinterpret_cast<T *>(&t) : &v.front();
+}
+
+/// @endcond
+
+/// @addtogroup flatbuffers_cpp_api
+/// @{
+/// @class FlatBufferBuilder
+/// @brief Helper class to hold data needed in creation of a FlatBuffer.
+/// To serialize data, you typically call one of the `Create*()` functions in
+/// the generated code, which in turn call a sequence of `StartTable`/
+/// `PushElement`/`AddElement`/`EndTable`, or the builtin `CreateString`/
+/// `CreateVector` functions. Do this is depth-first order to build up a tree to
+/// the root. `Finish()` wraps up the buffer ready for transport.
+class FlatBufferBuilder {
+ public:
+  /// @brief Default constructor for FlatBufferBuilder.
+  /// @param[in] initial_size The initial size of the buffer, in bytes. Defaults
+  /// to `1024`.
+  /// @param[in] allocator An `Allocator` to use. If null will use
+  /// `DefaultAllocator`.
+  /// @param[in] own_allocator Whether the builder/vector should own the
+  /// allocator. Defaults to / `false`.
+  /// @param[in] buffer_minalign Force the buffer to be aligned to the given
+  /// minimum alignment upon reallocation. Only needed if you intend to store
+  /// types with custom alignment AND you wish to read the buffer in-place
+  /// directly after creation.
+  explicit FlatBufferBuilder(
+      size_t initial_size = 1024, Allocator *allocator = nullptr,
+      bool own_allocator = false,
+      size_t buffer_minalign = AlignOf<largest_scalar_t>())
+      : buf_(initial_size, allocator, own_allocator, buffer_minalign),
+        num_field_loc(0),
+        max_voffset_(0),
+        nested(false),
+        finished(false),
+        minalign_(1),
+        force_defaults_(false),
+        dedup_vtables_(true),
+        string_pool(nullptr) {
+    EndianCheck();
+  }
+
+  // clang-format off
+  /// @brief Move constructor for FlatBufferBuilder.
+  #if !defined(FLATBUFFERS_CPP98_STL)
+  FlatBufferBuilder(FlatBufferBuilder &&other)
+  #else
+  FlatBufferBuilder(FlatBufferBuilder &other)
+  #endif  // #if !defined(FLATBUFFERS_CPP98_STL)
+    : buf_(1024, nullptr, false, AlignOf<largest_scalar_t>()),
+      num_field_loc(0),
+      max_voffset_(0),
+      nested(false),
+      finished(false),
+      minalign_(1),
+      force_defaults_(false),
+      dedup_vtables_(true),
+      string_pool(nullptr) {
+    EndianCheck();
+    // Default construct and swap idiom.
+    // Lack of delegating constructors in vs2010 makes it more verbose than needed.
+    Swap(other);
+  }
+  // clang-format on
+
+  // clang-format off
+  #if !defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+  /// @brief Move assignment operator for FlatBufferBuilder.
+  FlatBufferBuilder &operator=(FlatBufferBuilder &&other) {
+    // Move construct a temporary and swap idiom
+    FlatBufferBuilder temp(std::move(other));
+    Swap(temp);
+    return *this;
+  }
+  // clang-format off
+  #endif  // defined(FLATBUFFERS_CPP98_STL)
+  // clang-format on
+
+  void Swap(FlatBufferBuilder &other) {
+    using std::swap;
+    buf_.swap(other.buf_);
+    swap(num_field_loc, other.num_field_loc);
+    swap(max_voffset_, other.max_voffset_);
+    swap(nested, other.nested);
+    swap(finished, other.finished);
+    swap(minalign_, other.minalign_);
+    swap(force_defaults_, other.force_defaults_);
+    swap(dedup_vtables_, other.dedup_vtables_);
+    swap(string_pool, other.string_pool);
+  }
+
+  ~FlatBufferBuilder() {
+    if (string_pool) delete string_pool;
+  }
+
+  void Reset() {
+    Clear();       // clear builder state
+    buf_.reset();  // deallocate buffer
+  }
+
+  /// @brief Reset all the state in this FlatBufferBuilder so it can be reused
+  /// to construct another buffer.
+  void Clear() {
+    ClearOffsets();
+    buf_.clear();
+    nested = false;
+    finished = false;
+    minalign_ = 1;
+    if (string_pool) string_pool->clear();
+  }
+
+  /// @brief The current size of the serialized buffer, counting from the end.
+  /// @return Returns an `uoffset_t` with the current size of the buffer.
+  uoffset_t GetSize() const { return buf_.size(); }
+
+  /// @brief Get the serialized buffer (after you call `Finish()`).
+  /// @return Returns an `uint8_t` pointer to the FlatBuffer data inside the
+  /// buffer.
+  uint8_t *GetBufferPointer() const {
+    Finished();
+    return buf_.data();
+  }
+
+  /// @brief Get a pointer to an unfinished buffer.
+  /// @return Returns a `uint8_t` pointer to the unfinished buffer.
+  uint8_t *GetCurrentBufferPointer() const { return buf_.data(); }
+
+  /// @brief Get the released pointer to the serialized buffer.
+  /// @warning Do NOT attempt to use this FlatBufferBuilder afterwards!
+  /// @return A `FlatBuffer` that owns the buffer and its allocator and
+  /// behaves similar to a `unique_ptr` with a deleter.
+  FLATBUFFERS_ATTRIBUTE(deprecated("use Release() instead"))
+  DetachedBuffer ReleaseBufferPointer() {
+    Finished();
+    return buf_.release();
+  }
+
+  /// @brief Get the released DetachedBuffer.
+  /// @return A `DetachedBuffer` that owns the buffer and its allocator.
+  DetachedBuffer Release() {
+    Finished();
+    return buf_.release();
+  }
+
+  /// @brief Get the released pointer to the serialized buffer.
+  /// @param size The size of the memory block containing
+  /// the serialized `FlatBuffer`.
+  /// @param offset The offset from the released pointer where the finished
+  /// `FlatBuffer` starts.
+  /// @return A raw pointer to the start of the memory block containing
+  /// the serialized `FlatBuffer`.
+  /// @remark If the allocator is owned, it gets deleted when the destructor is
+  /// called..
+  uint8_t *ReleaseRaw(size_t &size, size_t &offset) {
+    Finished();
+    return buf_.release_raw(size, offset);
+  }
+
+  /// @brief get the minimum alignment this buffer needs to be accessed
+  /// properly. This is only known once all elements have been written (after
+  /// you call Finish()). You can use this information if you need to embed
+  /// a FlatBuffer in some other buffer, such that you can later read it
+  /// without first having to copy it into its own buffer.
+  size_t GetBufferMinAlignment() {
+    Finished();
+    return minalign_;
+  }
+
+  /// @cond FLATBUFFERS_INTERNAL
+  void Finished() const {
+    // If you get this assert, you're attempting to get access a buffer
+    // which hasn't been finished yet. Be sure to call
+    // FlatBufferBuilder::Finish with your root table.
+    // If you really need to access an unfinished buffer, call
+    // GetCurrentBufferPointer instead.
+    FLATBUFFERS_ASSERT(finished);
+  }
+  /// @endcond
+
+  /// @brief In order to save space, fields that are set to their default value
+  /// don't get serialized into the buffer.
+  /// @param[in] fd When set to `true`, always serializes default values that
+  /// are set. Optional fields which are not set explicitly, will still not be
+  /// serialized.
+  void ForceDefaults(bool fd) { force_defaults_ = fd; }
+
+  /// @brief By default vtables are deduped in order to save space.
+  /// @param[in] dedup When set to `true`, dedup vtables.
+  void DedupVtables(bool dedup) { dedup_vtables_ = dedup; }
+
+  /// @cond FLATBUFFERS_INTERNAL
+  void Pad(size_t num_bytes) { buf_.fill(num_bytes); }
+
+  void TrackMinAlign(size_t elem_size) {
+    if (elem_size > minalign_) minalign_ = elem_size;
+  }
+
+  void Align(size_t elem_size) {
+    TrackMinAlign(elem_size);
+    buf_.fill(PaddingBytes(buf_.size(), elem_size));
+  }
+
+  void PushFlatBuffer(const uint8_t *bytes, size_t size) {
+    PushBytes(bytes, size);
+    finished = true;
+  }
+
+  void PushBytes(const uint8_t *bytes, size_t size) { buf_.push(bytes, size); }
+
+  void PopBytes(size_t amount) { buf_.pop(amount); }
+
+  template<typename T> void AssertScalarT() {
+    // The code assumes power of 2 sizes and endian-swap-ability.
+    static_assert(flatbuffers::is_scalar<T>::value, "T must be a scalar type");
+  }
+
+  // Write a single aligned scalar to the buffer
+  template<typename T> uoffset_t PushElement(T element) {
+    AssertScalarT<T>();
+    T litle_endian_element = EndianScalar(element);
+    Align(sizeof(T));
+    buf_.push_small(litle_endian_element);
+    return GetSize();
+  }
+
+  template<typename T> uoffset_t PushElement(Offset<T> off) {
+    // Special case for offsets: see ReferTo below.
+    return PushElement(ReferTo(off.o));
+  }
+
+  // When writing fields, we track where they are, so we can create correct
+  // vtables later.
+  void TrackField(voffset_t field, uoffset_t off) {
+    FieldLoc fl = { off, field };
+    buf_.scratch_push_small(fl);
+    num_field_loc++;
+    max_voffset_ = (std::max)(max_voffset_, field);
+  }
+
+  // Like PushElement, but additionally tracks the field this represents.
+  template<typename T> void AddElement(voffset_t field, T e, T def) {
+    // We don't serialize values equal to the default.
+    if (IsTheSameAs(e, def) && !force_defaults_) return;
+    auto off = PushElement(e);
+    TrackField(field, off);
+  }
+
+  template<typename T> void AddOffset(voffset_t field, Offset<T> off) {
+    if (off.IsNull()) return;  // Don't store.
+    AddElement(field, ReferTo(off.o), static_cast<uoffset_t>(0));
+  }
+
+  template<typename T> void AddStruct(voffset_t field, const T *structptr) {
+    if (!structptr) return;  // Default, don't store.
+    Align(AlignOf<T>());
+    buf_.push_small(*structptr);
+    TrackField(field, GetSize());
+  }
+
+  void AddStructOffset(voffset_t field, uoffset_t off) {
+    TrackField(field, off);
+  }
+
+  // Offsets initially are relative to the end of the buffer (downwards).
+  // This function converts them to be relative to the current location
+  // in the buffer (when stored here), pointing upwards.
+  uoffset_t ReferTo(uoffset_t off) {
+    // Align to ensure GetSize() below is correct.
+    Align(sizeof(uoffset_t));
+    // Offset must refer to something already in buffer.
+    FLATBUFFERS_ASSERT(off && off <= GetSize());
+    return GetSize() - off + static_cast<uoffset_t>(sizeof(uoffset_t));
+  }
+
+  void NotNested() {
+    // If you hit this, you're trying to construct a Table/Vector/String
+    // during the construction of its parent table (between the MyTableBuilder
+    // and table.Finish().
+    // Move the creation of these sub-objects to above the MyTableBuilder to
+    // not get this assert.
+    // Ignoring this assert may appear to work in simple cases, but the reason
+    // it is here is that storing objects in-line may cause vtable offsets
+    // to not fit anymore. It also leads to vtable duplication.
+    FLATBUFFERS_ASSERT(!nested);
+    // If you hit this, fields were added outside the scope of a table.
+    FLATBUFFERS_ASSERT(!num_field_loc);
+  }
+
+  // From generated code (or from the parser), we call StartTable/EndTable
+  // with a sequence of AddElement calls in between.
+  uoffset_t StartTable() {
+    NotNested();
+    nested = true;
+    return GetSize();
+  }
+
+  // This finishes one serialized object by generating the vtable if it's a
+  // table, comparing it against existing vtables, and writing the
+  // resulting vtable offset.
+  uoffset_t EndTable(uoffset_t start) {
+    // If you get this assert, a corresponding StartTable wasn't called.
+    FLATBUFFERS_ASSERT(nested);
+    // Write the vtable offset, which is the start of any Table.
+    // We fill it's value later.
+    auto vtableoffsetloc = PushElement<soffset_t>(0);
+    // Write a vtable, which consists entirely of voffset_t elements.
+    // It starts with the number of offsets, followed by a type id, followed
+    // by the offsets themselves. In reverse:
+    // Include space for the last offset and ensure empty tables have a
+    // minimum size.
+    max_voffset_ =
+        (std::max)(static_cast<voffset_t>(max_voffset_ + sizeof(voffset_t)),
+                   FieldIndexToOffset(0));
+    buf_.fill_big(max_voffset_);
+    auto table_object_size = vtableoffsetloc - start;
+    // Vtable use 16bit offsets.
+    FLATBUFFERS_ASSERT(table_object_size < 0x10000);
+    WriteScalar<voffset_t>(buf_.data() + sizeof(voffset_t),
+                           static_cast<voffset_t>(table_object_size));
+    WriteScalar<voffset_t>(buf_.data(), max_voffset_);
+    // Write the offsets into the table
+    for (auto it = buf_.scratch_end() - num_field_loc * sizeof(FieldLoc);
+         it < buf_.scratch_end(); it += sizeof(FieldLoc)) {
+      auto field_location = reinterpret_cast<FieldLoc *>(it);
+      auto pos = static_cast<voffset_t>(vtableoffsetloc - field_location->off);
+      // If this asserts, it means you've set a field twice.
+      FLATBUFFERS_ASSERT(
+          !ReadScalar<voffset_t>(buf_.data() + field_location->id));
+      WriteScalar<voffset_t>(buf_.data() + field_location->id, pos);
+    }
+    ClearOffsets();
+    auto vt1 = reinterpret_cast<voffset_t *>(buf_.data());
+    auto vt1_size = ReadScalar<voffset_t>(vt1);
+    auto vt_use = GetSize();
+    // See if we already have generated a vtable with this exact same
+    // layout before. If so, make it point to the old one, remove this one.
+    if (dedup_vtables_) {
+      for (auto it = buf_.scratch_data(); it < buf_.scratch_end();
+           it += sizeof(uoffset_t)) {
+        auto vt_offset_ptr = reinterpret_cast<uoffset_t *>(it);
+        auto vt2 = reinterpret_cast<voffset_t *>(buf_.data_at(*vt_offset_ptr));
+        auto vt2_size = ReadScalar<voffset_t>(vt2);
+        if (vt1_size != vt2_size || 0 != memcmp(vt2, vt1, vt1_size)) continue;
+        vt_use = *vt_offset_ptr;
+        buf_.pop(GetSize() - vtableoffsetloc);
+        break;
+      }
+    }
+    // If this is a new vtable, remember it.
+    if (vt_use == GetSize()) { buf_.scratch_push_small(vt_use); }
+    // Fill the vtable offset we created above.
+    // The offset points from the beginning of the object to where the
+    // vtable is stored.
+    // Offsets default direction is downward in memory for future format
+    // flexibility (storing all vtables at the start of the file).
+    WriteScalar(buf_.data_at(vtableoffsetloc),
+                static_cast<soffset_t>(vt_use) -
+                    static_cast<soffset_t>(vtableoffsetloc));
+
+    nested = false;
+    return vtableoffsetloc;
+  }
+
+  FLATBUFFERS_ATTRIBUTE(deprecated("call the version above instead"))
+  uoffset_t EndTable(uoffset_t start, voffset_t /*numfields*/) {
+    return EndTable(start);
+  }
+
+  // This checks a required field has been set in a given table that has
+  // just been constructed.
+  template<typename T> void Required(Offset<T> table, voffset_t field);
+
+  uoffset_t StartStruct(size_t alignment) {
+    Align(alignment);
+    return GetSize();
+  }
+
+  uoffset_t EndStruct() { return GetSize(); }
+
+  void ClearOffsets() {
+    buf_.scratch_pop(num_field_loc * sizeof(FieldLoc));
+    num_field_loc = 0;
+    max_voffset_ = 0;
+  }
+
+  // Aligns such that when "len" bytes are written, an object can be written
+  // after it with "alignment" without padding.
+  void PreAlign(size_t len, size_t alignment) {
+    TrackMinAlign(alignment);
+    buf_.fill(PaddingBytes(GetSize() + len, alignment));
+  }
+  template<typename T> void PreAlign(size_t len) {
+    AssertScalarT<T>();
+    PreAlign(len, sizeof(T));
+  }
+  /// @endcond
+
+  /// @brief Store a string in the buffer, which can contain any binary data.
+  /// @param[in] str A const char pointer to the data to be stored as a string.
+  /// @param[in] len The number of bytes that should be stored from `str`.
+  /// @return Returns the offset in the buffer where the string starts.
+  Offset<String> CreateString(const char *str, size_t len) {
+    NotNested();
+    PreAlign<uoffset_t>(len + 1);  // Always 0-terminated.
+    buf_.fill(1);
+    PushBytes(reinterpret_cast<const uint8_t *>(str), len);
+    PushElement(static_cast<uoffset_t>(len));
+    return Offset<String>(GetSize());
+  }
+
+  /// @brief Store a string in the buffer, which is null-terminated.
+  /// @param[in] str A const char pointer to a C-string to add to the buffer.
+  /// @return Returns the offset in the buffer where the string starts.
+  Offset<String> CreateString(const char *str) {
+    return CreateString(str, strlen(str));
+  }
+
+  /// @brief Store a string in the buffer, which is null-terminated.
+  /// @param[in] str A char pointer to a C-string to add to the buffer.
+  /// @return Returns the offset in the buffer where the string starts.
+  Offset<String> CreateString(char *str) {
+    return CreateString(str, strlen(str));
+  }
+
+  /// @brief Store a string in the buffer, which can contain any binary data.
+  /// @param[in] str A const reference to a std::string to store in the buffer.
+  /// @return Returns the offset in the buffer where the string starts.
+  Offset<String> CreateString(const std::string &str) {
+    return CreateString(str.c_str(), str.length());
+  }
+
+  // clang-format off
+  #ifdef FLATBUFFERS_HAS_STRING_VIEW
+  /// @brief Store a string in the buffer, which can contain any binary data.
+  /// @param[in] str A const string_view to copy in to the buffer.
+  /// @return Returns the offset in the buffer where the string starts.
+  Offset<String> CreateString(flatbuffers::string_view str) {
+    return CreateString(str.data(), str.size());
+  }
+  #endif // FLATBUFFERS_HAS_STRING_VIEW
+  // clang-format on
+
+  /// @brief Store a string in the buffer, which can contain any binary data.
+  /// @param[in] str A const pointer to a `String` struct to add to the buffer.
+  /// @return Returns the offset in the buffer where the string starts
+  Offset<String> CreateString(const String *str) {
+    return str ? CreateString(str->c_str(), str->size()) : 0;
+  }
+
+  /// @brief Store a string in the buffer, which can contain any binary data.
+  /// @param[in] str A const reference to a std::string like type with support
+  /// of T::c_str() and T::length() to store in the buffer.
+  /// @return Returns the offset in the buffer where the string starts.
+  template<typename T> Offset<String> CreateString(const T &str) {
+    return CreateString(str.c_str(), str.length());
+  }
+
+  /// @brief Store a string in the buffer, which can contain any binary data.
+  /// If a string with this exact contents has already been serialized before,
+  /// instead simply returns the offset of the existing string.
+  /// @param[in] str A const char pointer to the data to be stored as a string.
+  /// @param[in] len The number of bytes that should be stored from `str`.
+  /// @return Returns the offset in the buffer where the string starts.
+  Offset<String> CreateSharedString(const char *str, size_t len) {
+    if (!string_pool)
+      string_pool = new StringOffsetMap(StringOffsetCompare(buf_));
+    auto size_before_string = buf_.size();
+    // Must first serialize the string, since the set is all offsets into
+    // buffer.
+    auto off = CreateString(str, len);
+    auto it = string_pool->find(off);
+    // If it exists we reuse existing serialized data!
+    if (it != string_pool->end()) {
+      // We can remove the string we serialized.
+      buf_.pop(buf_.size() - size_before_string);
+      return *it;
+    }
+    // Record this string for future use.
+    string_pool->insert(off);
+    return off;
+  }
+
+  /// @brief Store a string in the buffer, which null-terminated.
+  /// If a string with this exact contents has already been serialized before,
+  /// instead simply returns the offset of the existing string.
+  /// @param[in] str A const char pointer to a C-string to add to the buffer.
+  /// @return Returns the offset in the buffer where the string starts.
+  Offset<String> CreateSharedString(const char *str) {
+    return CreateSharedString(str, strlen(str));
+  }
+
+  /// @brief Store a string in the buffer, which can contain any binary data.
+  /// If a string with this exact contents has already been serialized before,
+  /// instead simply returns the offset of the existing string.
+  /// @param[in] str A const reference to a std::string to store in the buffer.
+  /// @return Returns the offset in the buffer where the string starts.
+  Offset<String> CreateSharedString(const std::string &str) {
+    return CreateSharedString(str.c_str(), str.length());
+  }
+
+  /// @brief Store a string in the buffer, which can contain any binary data.
+  /// If a string with this exact contents has already been serialized before,
+  /// instead simply returns the offset of the existing string.
+  /// @param[in] str A const pointer to a `String` struct to add to the buffer.
+  /// @return Returns the offset in the buffer where the string starts
+  Offset<String> CreateSharedString(const String *str) {
+    return CreateSharedString(str->c_str(), str->size());
+  }
+
+  /// @cond FLATBUFFERS_INTERNAL
+  uoffset_t EndVector(size_t len) {
+    FLATBUFFERS_ASSERT(nested);  // Hit if no corresponding StartVector.
+    nested = false;
+    return PushElement(static_cast<uoffset_t>(len));
+  }
+
+  void StartVector(size_t len, size_t elemsize) {
+    NotNested();
+    nested = true;
+    PreAlign<uoffset_t>(len * elemsize);
+    PreAlign(len * elemsize, elemsize);  // Just in case elemsize > uoffset_t.
+  }
+
+  // Call this right before StartVector/CreateVector if you want to force the
+  // alignment to be something different than what the element size would
+  // normally dictate.
+  // This is useful when storing a nested_flatbuffer in a vector of bytes,
+  // or when storing SIMD floats, etc.
+  void ForceVectorAlignment(size_t len, size_t elemsize, size_t alignment) {
+    PreAlign(len * elemsize, alignment);
+  }
+
+  // Similar to ForceVectorAlignment but for String fields.
+  void ForceStringAlignment(size_t len, size_t alignment) {
+    PreAlign((len + 1) * sizeof(char), alignment);
+  }
+
+  /// @endcond
+
+  /// @brief Serialize an array into a FlatBuffer `vector`.
+  /// @tparam T The data type of the array elements.
+  /// @param[in] v A pointer to the array of type `T` to serialize into the
+  /// buffer as a `vector`.
+  /// @param[in] len The number of elements to serialize.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T> Offset<Vector<T>> CreateVector(const T *v, size_t len) {
+    // If this assert hits, you're specifying a template argument that is
+    // causing the wrong overload to be selected, remove it.
+    AssertScalarT<T>();
+    StartVector(len, sizeof(T));
+    // clang-format off
+    #if FLATBUFFERS_LITTLEENDIAN
+      PushBytes(reinterpret_cast<const uint8_t *>(v), len * sizeof(T));
+    #else
+      if (sizeof(T) == 1) {
+        PushBytes(reinterpret_cast<const uint8_t *>(v), len);
+      } else {
+        for (auto i = len; i > 0; ) {
+          PushElement(v[--i]);
+        }
+      }
+    #endif
+    // clang-format on
+    return Offset<Vector<T>>(EndVector(len));
+  }
+
+  template<typename T>
+  Offset<Vector<Offset<T>>> CreateVector(const Offset<T> *v, size_t len) {
+    StartVector(len, sizeof(Offset<T>));
+    for (auto i = len; i > 0;) { PushElement(v[--i]); }
+    return Offset<Vector<Offset<T>>>(EndVector(len));
+  }
+
+  /// @brief Serialize a `std::vector` into a FlatBuffer `vector`.
+  /// @tparam T The data type of the `std::vector` elements.
+  /// @param v A const reference to the `std::vector` to serialize into the
+  /// buffer as a `vector`.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T> Offset<Vector<T>> CreateVector(const std::vector<T> &v) {
+    return CreateVector(data(v), v.size());
+  }
+
+  // vector<bool> may be implemented using a bit-set, so we can't access it as
+  // an array. Instead, read elements manually.
+  // Background: https://isocpp.org/blog/2012/11/on-vectorbool
+  Offset<Vector<uint8_t>> CreateVector(const std::vector<bool> &v) {
+    StartVector(v.size(), sizeof(uint8_t));
+    for (auto i = v.size(); i > 0;) {
+      PushElement(static_cast<uint8_t>(v[--i]));
+    }
+    return Offset<Vector<uint8_t>>(EndVector(v.size()));
+  }
+
+  // clang-format off
+  #ifndef FLATBUFFERS_CPP98_STL
+  /// @brief Serialize values returned by a function into a FlatBuffer `vector`.
+  /// This is a convenience function that takes care of iteration for you.
+  /// @tparam T The data type of the `std::vector` elements.
+  /// @param f A function that takes the current iteration 0..vector_size-1 and
+  /// returns any type that you can construct a FlatBuffers vector out of.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T> Offset<Vector<T>> CreateVector(size_t vector_size,
+      const std::function<T (size_t i)> &f) {
+    std::vector<T> elems(vector_size);
+    for (size_t i = 0; i < vector_size; i++) elems[i] = f(i);
+    return CreateVector(elems);
+  }
+  #endif
+  // clang-format on
+
+  /// @brief Serialize values returned by a function into a FlatBuffer `vector`.
+  /// This is a convenience function that takes care of iteration for you.
+  /// @tparam T The data type of the `std::vector` elements.
+  /// @param f A function that takes the current iteration 0..vector_size-1,
+  /// and the state parameter returning any type that you can construct a
+  /// FlatBuffers vector out of.
+  /// @param state State passed to f.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T, typename F, typename S>
+  Offset<Vector<T>> CreateVector(size_t vector_size, F f, S *state) {
+    std::vector<T> elems(vector_size);
+    for (size_t i = 0; i < vector_size; i++) elems[i] = f(i, state);
+    return CreateVector(elems);
+  }
+
+  /// @brief Serialize a `std::vector<std::string>` into a FlatBuffer `vector`.
+  /// This is a convenience function for a common case.
+  /// @param v A const reference to the `std::vector` to serialize into the
+  /// buffer as a `vector`.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  Offset<Vector<Offset<String>>> CreateVectorOfStrings(
+      const std::vector<std::string> &v) {
+    std::vector<Offset<String>> offsets(v.size());
+    for (size_t i = 0; i < v.size(); i++) offsets[i] = CreateString(v[i]);
+    return CreateVector(offsets);
+  }
+
+  /// @brief Serialize an array of structs into a FlatBuffer `vector`.
+  /// @tparam T The data type of the struct array elements.
+  /// @param[in] v A pointer to the array of type `T` to serialize into the
+  /// buffer as a `vector`.
+  /// @param[in] len The number of elements to serialize.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T>
+  Offset<Vector<const T *>> CreateVectorOfStructs(const T *v, size_t len) {
+    StartVector(len * sizeof(T) / AlignOf<T>(), AlignOf<T>());
+    PushBytes(reinterpret_cast<const uint8_t *>(v), sizeof(T) * len);
+    return Offset<Vector<const T *>>(EndVector(len));
+  }
+
+  /// @brief Serialize an array of native structs into a FlatBuffer `vector`.
+  /// @tparam T The data type of the struct array elements.
+  /// @tparam S The data type of the native struct array elements.
+  /// @param[in] v A pointer to the array of type `S` to serialize into the
+  /// buffer as a `vector`.
+  /// @param[in] len The number of elements to serialize.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T, typename S>
+  Offset<Vector<const T *>> CreateVectorOfNativeStructs(const S *v,
+                                                        size_t len) {
+    extern T Pack(const S &);
+    std::vector<T> vv(len);
+    std::transform(v, v + len, vv.begin(), Pack);
+    return CreateVectorOfStructs<T>(data(vv), vv.size());
+  }
+
+  // clang-format off
+  #ifndef FLATBUFFERS_CPP98_STL
+  /// @brief Serialize an array of structs into a FlatBuffer `vector`.
+  /// @tparam T The data type of the struct array elements.
+  /// @param[in] filler A function that takes the current iteration 0..vector_size-1
+  /// and a pointer to the struct that must be filled.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  /// This is mostly useful when flatbuffers are generated with mutation
+  /// accessors.
+  template<typename T> Offset<Vector<const T *>> CreateVectorOfStructs(
+      size_t vector_size, const std::function<void(size_t i, T *)> &filler) {
+    T* structs = StartVectorOfStructs<T>(vector_size);
+    for (size_t i = 0; i < vector_size; i++) {
+      filler(i, structs);
+      structs++;
+    }
+    return EndVectorOfStructs<T>(vector_size);
+  }
+  #endif
+  // clang-format on
+
+  /// @brief Serialize an array of structs into a FlatBuffer `vector`.
+  /// @tparam T The data type of the struct array elements.
+  /// @param[in] f A function that takes the current iteration 0..vector_size-1,
+  /// a pointer to the struct that must be filled and the state argument.
+  /// @param[in] state Arbitrary state to pass to f.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  /// This is mostly useful when flatbuffers are generated with mutation
+  /// accessors.
+  template<typename T, typename F, typename S>
+  Offset<Vector<const T *>> CreateVectorOfStructs(size_t vector_size, F f,
+                                                  S *state) {
+    T *structs = StartVectorOfStructs<T>(vector_size);
+    for (size_t i = 0; i < vector_size; i++) {
+      f(i, structs, state);
+      structs++;
+    }
+    return EndVectorOfStructs<T>(vector_size);
+  }
+
+  /// @brief Serialize a `std::vector` of structs into a FlatBuffer `vector`.
+  /// @tparam T The data type of the `std::vector` struct elements.
+  /// @param[in] v A const reference to the `std::vector` of structs to
+  /// serialize into the buffer as a `vector`.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T, typename Alloc>
+  Offset<Vector<const T *>> CreateVectorOfStructs(
+      const std::vector<T, Alloc> &v) {
+    return CreateVectorOfStructs(data(v), v.size());
+  }
+
+  /// @brief Serialize a `std::vector` of native structs into a FlatBuffer
+  /// `vector`.
+  /// @tparam T The data type of the `std::vector` struct elements.
+  /// @tparam S The data type of the `std::vector` native struct elements.
+  /// @param[in] v A const reference to the `std::vector` of structs to
+  /// serialize into the buffer as a `vector`.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T, typename S>
+  Offset<Vector<const T *>> CreateVectorOfNativeStructs(
+      const std::vector<S> &v) {
+    return CreateVectorOfNativeStructs<T, S>(data(v), v.size());
+  }
+
+  /// @cond FLATBUFFERS_INTERNAL
+  template<typename T> struct StructKeyComparator {
+    bool operator()(const T &a, const T &b) const {
+      return a.KeyCompareLessThan(&b);
+    }
+
+   private:
+    StructKeyComparator &operator=(const StructKeyComparator &);
+  };
+  /// @endcond
+
+  /// @brief Serialize a `std::vector` of structs into a FlatBuffer `vector`
+  /// in sorted order.
+  /// @tparam T The data type of the `std::vector` struct elements.
+  /// @param[in] v A const reference to the `std::vector` of structs to
+  /// serialize into the buffer as a `vector`.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T>
+  Offset<Vector<const T *>> CreateVectorOfSortedStructs(std::vector<T> *v) {
+    return CreateVectorOfSortedStructs(data(*v), v->size());
+  }
+
+  /// @brief Serialize a `std::vector` of native structs into a FlatBuffer
+  /// `vector` in sorted order.
+  /// @tparam T The data type of the `std::vector` struct elements.
+  /// @tparam S The data type of the `std::vector` native struct elements.
+  /// @param[in] v A const reference to the `std::vector` of structs to
+  /// serialize into the buffer as a `vector`.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T, typename S>
+  Offset<Vector<const T *>> CreateVectorOfSortedNativeStructs(
+      std::vector<S> *v) {
+    return CreateVectorOfSortedNativeStructs<T, S>(data(*v), v->size());
+  }
+
+  /// @brief Serialize an array of structs into a FlatBuffer `vector` in sorted
+  /// order.
+  /// @tparam T The data type of the struct array elements.
+  /// @param[in] v A pointer to the array of type `T` to serialize into the
+  /// buffer as a `vector`.
+  /// @param[in] len The number of elements to serialize.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T>
+  Offset<Vector<const T *>> CreateVectorOfSortedStructs(T *v, size_t len) {
+    std::sort(v, v + len, StructKeyComparator<T>());
+    return CreateVectorOfStructs(v, len);
+  }
+
+  /// @brief Serialize an array of native structs into a FlatBuffer `vector` in
+  /// sorted order.
+  /// @tparam T The data type of the struct array elements.
+  /// @tparam S The data type of the native struct array elements.
+  /// @param[in] v A pointer to the array of type `S` to serialize into the
+  /// buffer as a `vector`.
+  /// @param[in] len The number of elements to serialize.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T, typename S>
+  Offset<Vector<const T *>> CreateVectorOfSortedNativeStructs(S *v,
+                                                              size_t len) {
+    extern T Pack(const S &);
+    typedef T (*Pack_t)(const S &);
+    std::vector<T> vv(len);
+    std::transform(v, v + len, vv.begin(), static_cast<Pack_t &>(Pack));
+    return CreateVectorOfSortedStructs<T>(vv, len);
+  }
+
+  /// @cond FLATBUFFERS_INTERNAL
+  template<typename T> struct TableKeyComparator {
+    TableKeyComparator(vector_downward &buf) : buf_(buf) {}
+    TableKeyComparator(const TableKeyComparator &other) : buf_(other.buf_) {}
+    bool operator()(const Offset<T> &a, const Offset<T> &b) const {
+      auto table_a = reinterpret_cast<T *>(buf_.data_at(a.o));
+      auto table_b = reinterpret_cast<T *>(buf_.data_at(b.o));
+      return table_a->KeyCompareLessThan(table_b);
+    }
+    vector_downward &buf_;
+
+   private:
+    TableKeyComparator &operator=(const TableKeyComparator &other) {
+      buf_ = other.buf_;
+      return *this;
+    }
+  };
+  /// @endcond
+
+  /// @brief Serialize an array of `table` offsets as a `vector` in the buffer
+  /// in sorted order.
+  /// @tparam T The data type that the offset refers to.
+  /// @param[in] v An array of type `Offset<T>` that contains the `table`
+  /// offsets to store in the buffer in sorted order.
+  /// @param[in] len The number of elements to store in the `vector`.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T>
+  Offset<Vector<Offset<T>>> CreateVectorOfSortedTables(Offset<T> *v,
+                                                       size_t len) {
+    std::sort(v, v + len, TableKeyComparator<T>(buf_));
+    return CreateVector(v, len);
+  }
+
+  /// @brief Serialize an array of `table` offsets as a `vector` in the buffer
+  /// in sorted order.
+  /// @tparam T The data type that the offset refers to.
+  /// @param[in] v An array of type `Offset<T>` that contains the `table`
+  /// offsets to store in the buffer in sorted order.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T>
+  Offset<Vector<Offset<T>>> CreateVectorOfSortedTables(
+      std::vector<Offset<T>> *v) {
+    return CreateVectorOfSortedTables(data(*v), v->size());
+  }
+
+  /// @brief Specialized version of `CreateVector` for non-copying use cases.
+  /// Write the data any time later to the returned buffer pointer `buf`.
+  /// @param[in] len The number of elements to store in the `vector`.
+  /// @param[in] elemsize The size of each element in the `vector`.
+  /// @param[out] buf A pointer to a `uint8_t` pointer that can be
+  /// written to at a later time to serialize the data into a `vector`
+  /// in the buffer.
+  uoffset_t CreateUninitializedVector(size_t len, size_t elemsize,
+                                      uint8_t **buf) {
+    NotNested();
+    StartVector(len, elemsize);
+    buf_.make_space(len * elemsize);
+    auto vec_start = GetSize();
+    auto vec_end = EndVector(len);
+    *buf = buf_.data_at(vec_start);
+    return vec_end;
+  }
+
+  /// @brief Specialized version of `CreateVector` for non-copying use cases.
+  /// Write the data any time later to the returned buffer pointer `buf`.
+  /// @tparam T The data type of the data that will be stored in the buffer
+  /// as a `vector`.
+  /// @param[in] len The number of elements to store in the `vector`.
+  /// @param[out] buf A pointer to a pointer of type `T` that can be
+  /// written to at a later time to serialize the data into a `vector`
+  /// in the buffer.
+  template<typename T>
+  Offset<Vector<T>> CreateUninitializedVector(size_t len, T **buf) {
+    AssertScalarT<T>();
+    return CreateUninitializedVector(len, sizeof(T),
+                                     reinterpret_cast<uint8_t **>(buf));
+  }
+
+  template<typename T>
+  Offset<Vector<const T *>> CreateUninitializedVectorOfStructs(size_t len,
+                                                               T **buf) {
+    return CreateUninitializedVector(len, sizeof(T),
+                                     reinterpret_cast<uint8_t **>(buf));
+  }
+
+  // @brief Create a vector of scalar type T given as input a vector of scalar
+  // type U, useful with e.g. pre "enum class" enums, or any existing scalar
+  // data of the wrong type.
+  template<typename T, typename U>
+  Offset<Vector<T>> CreateVectorScalarCast(const U *v, size_t len) {
+    AssertScalarT<T>();
+    AssertScalarT<U>();
+    StartVector(len, sizeof(T));
+    for (auto i = len; i > 0;) { PushElement(static_cast<T>(v[--i])); }
+    return Offset<Vector<T>>(EndVector(len));
+  }
+
+  /// @brief Write a struct by itself, typically to be part of a union.
+  template<typename T> Offset<const T *> CreateStruct(const T &structobj) {
+    NotNested();
+    Align(AlignOf<T>());
+    buf_.push_small(structobj);
+    return Offset<const T *>(GetSize());
+  }
+
+  /// @brief The length of a FlatBuffer file header.
+  static const size_t kFileIdentifierLength = 4;
+
+  /// @brief Finish serializing a buffer by writing the root offset.
+  /// @param[in] file_identifier If a `file_identifier` is given, the buffer
+  /// will be prefixed with a standard FlatBuffers file header.
+  template<typename T>
+  void Finish(Offset<T> root, const char *file_identifier = nullptr) {
+    Finish(root.o, file_identifier, false);
+  }
+
+  /// @brief Finish a buffer with a 32 bit size field pre-fixed (size of the
+  /// buffer following the size field). These buffers are NOT compatible
+  /// with standard buffers created by Finish, i.e. you can't call GetRoot
+  /// on them, you have to use GetSizePrefixedRoot instead.
+  /// All >32 bit quantities in this buffer will be aligned when the whole
+  /// size pre-fixed buffer is aligned.
+  /// These kinds of buffers are useful for creating a stream of FlatBuffers.
+  template<typename T>
+  void FinishSizePrefixed(Offset<T> root,
+                          const char *file_identifier = nullptr) {
+    Finish(root.o, file_identifier, true);
+  }
+
+  void SwapBufAllocator(FlatBufferBuilder &other) {
+    buf_.swap_allocator(other.buf_);
+  }
+
+ protected:
+  // You shouldn't really be copying instances of this class.
+  FlatBufferBuilder(const FlatBufferBuilder &);
+  FlatBufferBuilder &operator=(const FlatBufferBuilder &);
+
+  void Finish(uoffset_t root, const char *file_identifier, bool size_prefix) {
+    NotNested();
+    buf_.clear_scratch();
+    // This will cause the whole buffer to be aligned.
+    PreAlign((size_prefix ? sizeof(uoffset_t) : 0) + sizeof(uoffset_t) +
+                 (file_identifier ? kFileIdentifierLength : 0),
+             minalign_);
+    if (file_identifier) {
+      FLATBUFFERS_ASSERT(strlen(file_identifier) == kFileIdentifierLength);
+      PushBytes(reinterpret_cast<const uint8_t *>(file_identifier),
+                kFileIdentifierLength);
+    }
+    PushElement(ReferTo(root));  // Location of root.
+    if (size_prefix) { PushElement(GetSize()); }
+    finished = true;
+  }
+
+  struct FieldLoc {
+    uoffset_t off;
+    voffset_t id;
+  };
+
+  vector_downward buf_;
+
+  // Accumulating offsets of table members while it is being built.
+  // We store these in the scratch pad of buf_, after the vtable offsets.
+  uoffset_t num_field_loc;
+  // Track how much of the vtable is in use, so we can output the most compact
+  // possible vtable.
+  voffset_t max_voffset_;
+
+  // Ensure objects are not nested.
+  bool nested;
+
+  // Ensure the buffer is finished before it is being accessed.
+  bool finished;
+
+  size_t minalign_;
+
+  bool force_defaults_;  // Serialize values equal to their defaults anyway.
+
+  bool dedup_vtables_;
+
+  struct StringOffsetCompare {
+    StringOffsetCompare(const vector_downward &buf) : buf_(&buf) {}
+    bool operator()(const Offset<String> &a, const Offset<String> &b) const {
+      auto stra = reinterpret_cast<const String *>(buf_->data_at(a.o));
+      auto strb = reinterpret_cast<const String *>(buf_->data_at(b.o));
+      return StringLessThan(stra->data(), stra->size(), strb->data(),
+                            strb->size());
+    }
+    const vector_downward *buf_;
+  };
+
+  // For use with CreateSharedString. Instantiated on first use only.
+  typedef std::set<Offset<String>, StringOffsetCompare> StringOffsetMap;
+  StringOffsetMap *string_pool;
+
+ private:
+  // Allocates space for a vector of structures.
+  // Must be completed with EndVectorOfStructs().
+  template<typename T> T *StartVectorOfStructs(size_t vector_size) {
+    StartVector(vector_size * sizeof(T) / AlignOf<T>(), AlignOf<T>());
+    return reinterpret_cast<T *>(buf_.make_space(vector_size * sizeof(T)));
+  }
+
+  // End the vector of structues in the flatbuffers.
+  // Vector should have previously be started with StartVectorOfStructs().
+  template<typename T>
+  Offset<Vector<const T *>> EndVectorOfStructs(size_t vector_size) {
+    return Offset<Vector<const T *>>(EndVector(vector_size));
+  }
+};
+/// @}
+
+/// @cond FLATBUFFERS_INTERNAL
+// Helpers to get a typed pointer to the root object contained in the buffer.
+template<typename T> T *GetMutableRoot(void *buf) {
+  EndianCheck();
+  return reinterpret_cast<T *>(
+      reinterpret_cast<uint8_t *>(buf) +
+      EndianScalar(*reinterpret_cast<uoffset_t *>(buf)));
+}
+
+template<typename T> const T *GetRoot(const void *buf) {
+  return GetMutableRoot<T>(const_cast<void *>(buf));
+}
+
+template<typename T> const T *GetSizePrefixedRoot(const void *buf) {
+  return GetRoot<T>(reinterpret_cast<const uint8_t *>(buf) + sizeof(uoffset_t));
+}
+
+/// Helpers to get a typed pointer to objects that are currently being built.
+/// @warning Creating new objects will lead to reallocations and invalidates
+/// the pointer!
+template<typename T>
+T *GetMutableTemporaryPointer(FlatBufferBuilder &fbb, Offset<T> offset) {
+  return reinterpret_cast<T *>(fbb.GetCurrentBufferPointer() + fbb.GetSize() -
+                               offset.o);
+}
+
+template<typename T>
+const T *GetTemporaryPointer(FlatBufferBuilder &fbb, Offset<T> offset) {
+  return GetMutableTemporaryPointer<T>(fbb, offset);
+}
+
+/// @brief Get a pointer to the the file_identifier section of the buffer.
+/// @return Returns a const char pointer to the start of the file_identifier
+/// characters in the buffer.  The returned char * has length
+/// 'flatbuffers::FlatBufferBuilder::kFileIdentifierLength'.
+/// This function is UNDEFINED for FlatBuffers whose schema does not include
+/// a file_identifier (likely points at padding or the start of a the root
+/// vtable).
+inline const char *GetBufferIdentifier(const void *buf,
+                                       bool size_prefixed = false) {
+  return reinterpret_cast<const char *>(buf) +
+         ((size_prefixed) ? 2 * sizeof(uoffset_t) : sizeof(uoffset_t));
+}
+
+// Helper to see if the identifier in a buffer has the expected value.
+inline bool BufferHasIdentifier(const void *buf, const char *identifier,
+                                bool size_prefixed = false) {
+  return strncmp(GetBufferIdentifier(buf, size_prefixed), identifier,
+                 FlatBufferBuilder::kFileIdentifierLength) == 0;
+}
+
+// Helper class to verify the integrity of a FlatBuffer
+class Verifier FLATBUFFERS_FINAL_CLASS {
+ public:
+  Verifier(const uint8_t *buf, size_t buf_len, uoffset_t _max_depth = 64,
+           uoffset_t _max_tables = 1000000, bool _check_alignment = true)
+      : buf_(buf),
+        size_(buf_len),
+        depth_(0),
+        max_depth_(_max_depth),
+        num_tables_(0),
+        max_tables_(_max_tables),
+        upper_bound_(0),
+        check_alignment_(_check_alignment) {
+    FLATBUFFERS_ASSERT(size_ < FLATBUFFERS_MAX_BUFFER_SIZE);
+  }
+
+  // Central location where any verification failures register.
+  bool Check(bool ok) const {
+    // clang-format off
+    #ifdef FLATBUFFERS_DEBUG_VERIFICATION_FAILURE
+      FLATBUFFERS_ASSERT(ok);
+    #endif
+    #ifdef FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE
+      if (!ok)
+        upper_bound_ = 0;
+    #endif
+    // clang-format on
+    return ok;
+  }
+
+  // Verify any range within the buffer.
+  bool Verify(size_t elem, size_t elem_len) const {
+    // clang-format off
+    #ifdef FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE
+      auto upper_bound = elem + elem_len;
+      if (upper_bound_ < upper_bound)
+        upper_bound_ =  upper_bound;
+    #endif
+    // clang-format on
+    return Check(elem_len < size_ && elem <= size_ - elem_len);
+  }
+
+  template<typename T> bool VerifyAlignment(size_t elem) const {
+    return Check((elem & (sizeof(T) - 1)) == 0 || !check_alignment_);
+  }
+
+  // Verify a range indicated by sizeof(T).
+  template<typename T> bool Verify(size_t elem) const {
+    return VerifyAlignment<T>(elem) && Verify(elem, sizeof(T));
+  }
+
+  bool VerifyFromPointer(const uint8_t *p, size_t len) {
+    auto o = static_cast<size_t>(p - buf_);
+    return Verify(o, len);
+  }
+
+  // Verify relative to a known-good base pointer.
+  bool Verify(const uint8_t *base, voffset_t elem_off, size_t elem_len) const {
+    return Verify(static_cast<size_t>(base - buf_) + elem_off, elem_len);
+  }
+
+  template<typename T>
+  bool Verify(const uint8_t *base, voffset_t elem_off) const {
+    return Verify(static_cast<size_t>(base - buf_) + elem_off, sizeof(T));
+  }
+
+  // Verify a pointer (may be NULL) of a table type.
+  template<typename T> bool VerifyTable(const T *table) {
+    return !table || table->Verify(*this);
+  }
+
+  // Verify a pointer (may be NULL) of any vector type.
+  template<typename T> bool VerifyVector(const Vector<T> *vec) const {
+    return !vec || VerifyVectorOrString(reinterpret_cast<const uint8_t *>(vec),
+                                        sizeof(T));
+  }
+
+  // Verify a pointer (may be NULL) of a vector to struct.
+  template<typename T> bool VerifyVector(const Vector<const T *> *vec) const {
+    return VerifyVector(reinterpret_cast<const Vector<T> *>(vec));
+  }
+
+  // Verify a pointer (may be NULL) to string.
+  bool VerifyString(const String *str) const {
+    size_t end;
+    return !str || (VerifyVectorOrString(reinterpret_cast<const uint8_t *>(str),
+                                         1, &end) &&
+                    Verify(end, 1) &&           // Must have terminator
+                    Check(buf_[end] == '\0'));  // Terminating byte must be 0.
+  }
+
+  // Common code between vectors and strings.
+  bool VerifyVectorOrString(const uint8_t *vec, size_t elem_size,
+                            size_t *end = nullptr) const {
+    auto veco = static_cast<size_t>(vec - buf_);
+    // Check we can read the size field.
+    if (!Verify<uoffset_t>(veco)) return false;
+    // Check the whole array. If this is a string, the byte past the array
+    // must be 0.
+    auto size = ReadScalar<uoffset_t>(vec);
+    auto max_elems = FLATBUFFERS_MAX_BUFFER_SIZE / elem_size;
+    if (!Check(size < max_elems))
+      return false;  // Protect against byte_size overflowing.
+    auto byte_size = sizeof(size) + elem_size * size;
+    if (end) *end = veco + byte_size;
+    return Verify(veco, byte_size);
+  }
+
+  // Special case for string contents, after the above has been called.
+  bool VerifyVectorOfStrings(const Vector<Offset<String>> *vec) const {
+    if (vec) {
+      for (uoffset_t i = 0; i < vec->size(); i++) {
+        if (!VerifyString(vec->Get(i))) return false;
+      }
+    }
+    return true;
+  }
+
+  // Special case for table contents, after the above has been called.
+  template<typename T> bool VerifyVectorOfTables(const Vector<Offset<T>> *vec) {
+    if (vec) {
+      for (uoffset_t i = 0; i < vec->size(); i++) {
+        if (!vec->Get(i)->Verify(*this)) return false;
+      }
+    }
+    return true;
+  }
+
+  __supress_ubsan__("unsigned-integer-overflow") bool VerifyTableStart(
+      const uint8_t *table) {
+    // Check the vtable offset.
+    auto tableo = static_cast<size_t>(table - buf_);
+    if (!Verify<soffset_t>(tableo)) return false;
+    // This offset may be signed, but doing the subtraction unsigned always
+    // gives the result we want.
+    auto vtableo = tableo - static_cast<size_t>(ReadScalar<soffset_t>(table));
+    // Check the vtable size field, then check vtable fits in its entirety.
+    return VerifyComplexity() && Verify<voffset_t>(vtableo) &&
+           VerifyAlignment<voffset_t>(ReadScalar<voffset_t>(buf_ + vtableo)) &&
+           Verify(vtableo, ReadScalar<voffset_t>(buf_ + vtableo));
+  }
+
+  template<typename T>
+  bool VerifyBufferFromStart(const char *identifier, size_t start) {
+    if (identifier && (size_ < 2 * sizeof(flatbuffers::uoffset_t) ||
+                       !BufferHasIdentifier(buf_ + start, identifier))) {
+      return false;
+    }
+
+    // Call T::Verify, which must be in the generated code for this type.
+    auto o = VerifyOffset(start);
+    return o && reinterpret_cast<const T *>(buf_ + start + o)->Verify(*this)
+    // clang-format off
+    #ifdef FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE
+           && GetComputedSize()
+    #endif
+        ;
+    // clang-format on
+  }
+
+  // Verify this whole buffer, starting with root type T.
+  template<typename T> bool VerifyBuffer() { return VerifyBuffer<T>(nullptr); }
+
+  template<typename T> bool VerifyBuffer(const char *identifier) {
+    return VerifyBufferFromStart<T>(identifier, 0);
+  }
+
+  template<typename T> bool VerifySizePrefixedBuffer(const char *identifier) {
+    return Verify<uoffset_t>(0U) &&
+           ReadScalar<uoffset_t>(buf_) == size_ - sizeof(uoffset_t) &&
+           VerifyBufferFromStart<T>(identifier, sizeof(uoffset_t));
+  }
+
+  uoffset_t VerifyOffset(size_t start) const {
+    if (!Verify<uoffset_t>(start)) return 0;
+    auto o = ReadScalar<uoffset_t>(buf_ + start);
+    // May not point to itself.
+    if (!Check(o != 0)) return 0;
+    // Can't wrap around / buffers are max 2GB.
+    if (!Check(static_cast<soffset_t>(o) >= 0)) return 0;
+    // Must be inside the buffer to create a pointer from it (pointer outside
+    // buffer is UB).
+    if (!Verify(start + o, 1)) return 0;
+    return o;
+  }
+
+  uoffset_t VerifyOffset(const uint8_t *base, voffset_t start) const {
+    return VerifyOffset(static_cast<size_t>(base - buf_) + start);
+  }
+
+  // Called at the start of a table to increase counters measuring data
+  // structure depth and amount, and possibly bails out with false if
+  // limits set by the constructor have been hit. Needs to be balanced
+  // with EndTable().
+  bool VerifyComplexity() {
+    depth_++;
+    num_tables_++;
+    return Check(depth_ <= max_depth_ && num_tables_ <= max_tables_);
+  }
+
+  // Called at the end of a table to pop the depth count.
+  bool EndTable() {
+    depth_--;
+    return true;
+  }
+
+  // Returns the message size in bytes
+  size_t GetComputedSize() const {
+    // clang-format off
+    #ifdef FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE
+      uintptr_t size = upper_bound_;
+      // Align the size to uoffset_t
+      size = (size - 1 + sizeof(uoffset_t)) & ~(sizeof(uoffset_t) - 1);
+      return (size > size_) ?  0 : size;
+    #else
+      // Must turn on FLATBUFFERS_TRACK_VERIFIER_BUFFER_SIZE for this to work.
+      (void)upper_bound_;
+      FLATBUFFERS_ASSERT(false);
+      return 0;
+    #endif
+    // clang-format on
+  }
+
+ private:
+  const uint8_t *buf_;
+  size_t size_;
+  uoffset_t depth_;
+  uoffset_t max_depth_;
+  uoffset_t num_tables_;
+  uoffset_t max_tables_;
+  mutable size_t upper_bound_;
+  bool check_alignment_;
+};
+
+// Convenient way to bundle a buffer and its length, to pass it around
+// typed by its root.
+// A BufferRef does not own its buffer.
+struct BufferRefBase {};  // for std::is_base_of
+template<typename T> struct BufferRef : BufferRefBase {
+  BufferRef() : buf(nullptr), len(0), must_free(false) {}
+  BufferRef(uint8_t *_buf, uoffset_t _len)
+      : buf(_buf), len(_len), must_free(false) {}
+
+  ~BufferRef() {
+    if (must_free) free(buf);
+  }
+
+  const T *GetRoot() const { return flatbuffers::GetRoot<T>(buf); }
+
+  bool Verify() {
+    Verifier verifier(buf, len);
+    return verifier.VerifyBuffer<T>(nullptr);
+  }
+
+  uint8_t *buf;
+  uoffset_t len;
+  bool must_free;
+};
+
+// "structs" are flat structures that do not have an offset table, thus
+// always have all members present and do not support forwards/backwards
+// compatible extensions.
+
+class Struct FLATBUFFERS_FINAL_CLASS {
+ public:
+  template<typename T> T GetField(uoffset_t o) const {
+    return ReadScalar<T>(&data_[o]);
+  }
+
+  template<typename T> T GetStruct(uoffset_t o) const {
+    return reinterpret_cast<T>(&data_[o]);
+  }
+
+  const uint8_t *GetAddressOf(uoffset_t o) const { return &data_[o]; }
+  uint8_t *GetAddressOf(uoffset_t o) { return &data_[o]; }
+
+ private:
+  // private constructor & copy constructor: you obtain instances of this
+  // class by pointing to existing data only
+  Struct();
+  Struct(const Struct &);
+  Struct &operator=(const Struct &);
+
+  uint8_t data_[1];
+};
+
+// "tables" use an offset table (possibly shared) that allows fields to be
+// omitted and added at will, but uses an extra indirection to read.
+class Table {
+ public:
+  const uint8_t *GetVTable() const {
+    return data_ - ReadScalar<soffset_t>(data_);
+  }
+
+  // This gets the field offset for any of the functions below it, or 0
+  // if the field was not present.
+  voffset_t GetOptionalFieldOffset(voffset_t field) const {
+    // The vtable offset is always at the start.
+    auto vtable = GetVTable();
+    // The first element is the size of the vtable (fields + type id + itself).
+    auto vtsize = ReadScalar<voffset_t>(vtable);
+    // If the field we're accessing is outside the vtable, we're reading older
+    // data, so it's the same as if the offset was 0 (not present).
+    return field < vtsize ? ReadScalar<voffset_t>(vtable + field) : 0;
+  }
+
+  template<typename T> T GetField(voffset_t field, T defaultval) const {
+    auto field_offset = GetOptionalFieldOffset(field);
+    return field_offset ? ReadScalar<T>(data_ + field_offset) : defaultval;
+  }
+
+  template<typename P> P GetPointer(voffset_t field) {
+    auto field_offset = GetOptionalFieldOffset(field);
+    auto p = data_ + field_offset;
+    return field_offset ? reinterpret_cast<P>(p + ReadScalar<uoffset_t>(p))
+                        : nullptr;
+  }
+  template<typename P> P GetPointer(voffset_t field) const {
+    return const_cast<Table *>(this)->GetPointer<P>(field);
+  }
+
+  template<typename P> P GetStruct(voffset_t field) const {
+    auto field_offset = GetOptionalFieldOffset(field);
+    auto p = const_cast<uint8_t *>(data_ + field_offset);
+    return field_offset ? reinterpret_cast<P>(p) : nullptr;
+  }
+
+  template<typename T> bool SetField(voffset_t field, T val, T def) {
+    auto field_offset = GetOptionalFieldOffset(field);
+    if (!field_offset) return IsTheSameAs(val, def);
+    WriteScalar(data_ + field_offset, val);
+    return true;
+  }
+
+  bool SetPointer(voffset_t field, const uint8_t *val) {
+    auto field_offset = GetOptionalFieldOffset(field);
+    if (!field_offset) return false;
+    WriteScalar(data_ + field_offset,
+                static_cast<uoffset_t>(val - (data_ + field_offset)));
+    return true;
+  }
+
+  uint8_t *GetAddressOf(voffset_t field) {
+    auto field_offset = GetOptionalFieldOffset(field);
+    return field_offset ? data_ + field_offset : nullptr;
+  }
+  const uint8_t *GetAddressOf(voffset_t field) const {
+    return const_cast<Table *>(this)->GetAddressOf(field);
+  }
+
+  bool CheckField(voffset_t field) const {
+    return GetOptionalFieldOffset(field) != 0;
+  }
+
+  // Verify the vtable of this table.
+  // Call this once per table, followed by VerifyField once per field.
+  bool VerifyTableStart(Verifier &verifier) const {
+    return verifier.VerifyTableStart(data_);
+  }
+
+  // Verify a particular field.
+  template<typename T>
+  bool VerifyField(const Verifier &verifier, voffset_t field) const {
+    // Calling GetOptionalFieldOffset should be safe now thanks to
+    // VerifyTable().
+    auto field_offset = GetOptionalFieldOffset(field);
+    // Check the actual field.
+    return !field_offset || verifier.Verify<T>(data_, field_offset);
+  }
+
+  // VerifyField for required fields.
+  template<typename T>
+  bool VerifyFieldRequired(const Verifier &verifier, voffset_t field) const {
+    auto field_offset = GetOptionalFieldOffset(field);
+    return verifier.Check(field_offset != 0) &&
+           verifier.Verify<T>(data_, field_offset);
+  }
+
+  // Versions for offsets.
+  bool VerifyOffset(const Verifier &verifier, voffset_t field) const {
+    auto field_offset = GetOptionalFieldOffset(field);
+    return !field_offset || verifier.VerifyOffset(data_, field_offset);
+  }
+
+  bool VerifyOffsetRequired(const Verifier &verifier, voffset_t field) const {
+    auto field_offset = GetOptionalFieldOffset(field);
+    return verifier.Check(field_offset != 0) &&
+           verifier.VerifyOffset(data_, field_offset);
+  }
+
+ private:
+  // private constructor & copy constructor: you obtain instances of this
+  // class by pointing to existing data only
+  Table();
+  Table(const Table &other);
+  Table &operator=(const Table &);
+
+  uint8_t data_[1];
+};
+
+template<typename T>
+void FlatBufferBuilder::Required(Offset<T> table, voffset_t field) {
+  auto table_ptr = reinterpret_cast<const Table *>(buf_.data_at(table.o));
+  bool ok = table_ptr->GetOptionalFieldOffset(field) != 0;
+  // If this fails, the caller will show what field needs to be set.
+  FLATBUFFERS_ASSERT(ok);
+  (void)ok;
+}
+
+/// @brief This can compute the start of a FlatBuffer from a root pointer, i.e.
+/// it is the opposite transformation of GetRoot().
+/// This may be useful if you want to pass on a root and have the recipient
+/// delete the buffer afterwards.
+inline const uint8_t *GetBufferStartFromRootPointer(const void *root) {
+  auto table = reinterpret_cast<const Table *>(root);
+  auto vtable = table->GetVTable();
+  // Either the vtable is before the root or after the root.
+  auto start = (std::min)(vtable, reinterpret_cast<const uint8_t *>(root));
+  // Align to at least sizeof(uoffset_t).
+  start = reinterpret_cast<const uint8_t *>(reinterpret_cast<uintptr_t>(start) &
+                                            ~(sizeof(uoffset_t) - 1));
+  // Additionally, there may be a file_identifier in the buffer, and the root
+  // offset. The buffer may have been aligned to any size between
+  // sizeof(uoffset_t) and FLATBUFFERS_MAX_ALIGNMENT (see "force_align").
+  // Sadly, the exact alignment is only known when constructing the buffer,
+  // since it depends on the presence of values with said alignment properties.
+  // So instead, we simply look at the next uoffset_t values (root,
+  // file_identifier, and alignment padding) to see which points to the root.
+  // None of the other values can "impersonate" the root since they will either
+  // be 0 or four ASCII characters.
+  static_assert(FlatBufferBuilder::kFileIdentifierLength == sizeof(uoffset_t),
+                "file_identifier is assumed to be the same size as uoffset_t");
+  for (auto possible_roots = FLATBUFFERS_MAX_ALIGNMENT / sizeof(uoffset_t) + 1;
+       possible_roots; possible_roots--) {
+    start -= sizeof(uoffset_t);
+    if (ReadScalar<uoffset_t>(start) + start ==
+        reinterpret_cast<const uint8_t *>(root))
+      return start;
+  }
+  // We didn't find the root, either the "root" passed isn't really a root,
+  // or the buffer is corrupt.
+  // Assert, because calling this function with bad data may cause reads
+  // outside of buffer boundaries.
+  FLATBUFFERS_ASSERT(false);
+  return nullptr;
+}
+
+/// @brief This return the prefixed size of a FlatBuffer.
+inline uoffset_t GetPrefixedSize(const uint8_t *buf) {
+  return ReadScalar<uoffset_t>(buf);
+}
+
+// Base class for native objects (FlatBuffer data de-serialized into native
+// C++ data structures).
+// Contains no functionality, purely documentative.
+struct NativeTable {};
+
+/// @brief Function types to be used with resolving hashes into objects and
+/// back again. The resolver gets a pointer to a field inside an object API
+/// object that is of the type specified in the schema using the attribute
+/// `cpp_type` (it is thus important whatever you write to this address
+/// matches that type). The value of this field is initially null, so you
+/// may choose to implement a delayed binding lookup using this function
+/// if you wish. The resolver does the opposite lookup, for when the object
+/// is being serialized again.
+typedef uint64_t hash_value_t;
+// clang-format off
+#ifdef FLATBUFFERS_CPP98_STL
+  typedef void (*resolver_function_t)(void **pointer_adr, hash_value_t hash);
+  typedef hash_value_t (*rehasher_function_t)(void *pointer);
+#else
+  typedef std::function<void (void **pointer_adr, hash_value_t hash)>
+          resolver_function_t;
+  typedef std::function<hash_value_t (void *pointer)> rehasher_function_t;
+#endif
+// clang-format on
+
+// Helper function to test if a field is present, using any of the field
+// enums in the generated code.
+// `table` must be a generated table type. Since this is a template parameter,
+// this is not typechecked to be a subclass of Table, so beware!
+// Note: this function will return false for fields equal to the default
+// value, since they're not stored in the buffer (unless force_defaults was
+// used).
+template<typename T>
+bool IsFieldPresent(const T *table, typename T::FlatBuffersVTableOffset field) {
+  // Cast, since Table is a private baseclass of any table types.
+  return reinterpret_cast<const Table *>(table)->CheckField(
+      static_cast<voffset_t>(field));
+}
+
+// Utility function for reverse lookups on the EnumNames*() functions
+// (in the generated C++ code)
+// names must be NULL terminated.
+inline int LookupEnum(const char **names, const char *name) {
+  for (const char **p = names; *p; p++)
+    if (!strcmp(*p, name)) return static_cast<int>(p - names);
+  return -1;
+}
+
+// These macros allow us to layout a struct with a guarantee that they'll end
+// up looking the same on different compilers and platforms.
+// It does this by disallowing the compiler to do any padding, and then
+// does padding itself by inserting extra padding fields that make every
+// element aligned to its own size.
+// Additionally, it manually sets the alignment of the struct as a whole,
+// which is typically its largest element, or a custom size set in the schema
+// by the force_align attribute.
+// These are used in the generated code only.
+
+// clang-format off
+#if defined(_MSC_VER)
+  #define FLATBUFFERS_MANUALLY_ALIGNED_STRUCT(alignment) \
+    __pragma(pack(1)) \
+    struct __declspec(align(alignment))
+  #define FLATBUFFERS_STRUCT_END(name, size) \
+    __pragma(pack()) \
+    static_assert(sizeof(name) == size, "compiler breaks packing rules")
+#elif defined(__GNUC__) || defined(__clang__) || defined(__ICCARM__)
+  #define FLATBUFFERS_MANUALLY_ALIGNED_STRUCT(alignment) \
+    _Pragma("pack(1)") \
+    struct __attribute__((aligned(alignment)))
+  #define FLATBUFFERS_STRUCT_END(name, size) \
+    _Pragma("pack()") \
+    static_assert(sizeof(name) == size, "compiler breaks packing rules")
+#else
+  #error Unknown compiler, please define structure alignment macros
+#endif
+// clang-format on
+
+// Minimal reflection via code generation.
+// Besides full-fat reflection (see reflection.h) and parsing/printing by
+// loading schemas (see idl.h), we can also have code generation for mimimal
+// reflection data which allows pretty-printing and other uses without needing
+// a schema or a parser.
+// Generate code with --reflect-types (types only) or --reflect-names (names
+// also) to enable.
+// See minireflect.h for utilities using this functionality.
+
+// These types are organized slightly differently as the ones in idl.h.
+enum SequenceType { ST_TABLE, ST_STRUCT, ST_UNION, ST_ENUM };
+
+// Scalars have the same order as in idl.h
+// clang-format off
+#define FLATBUFFERS_GEN_ELEMENTARY_TYPES(ET) \
+  ET(ET_UTYPE) \
+  ET(ET_BOOL) \
+  ET(ET_CHAR) \
+  ET(ET_UCHAR) \
+  ET(ET_SHORT) \
+  ET(ET_USHORT) \
+  ET(ET_INT) \
+  ET(ET_UINT) \
+  ET(ET_LONG) \
+  ET(ET_ULONG) \
+  ET(ET_FLOAT) \
+  ET(ET_DOUBLE) \
+  ET(ET_STRING) \
+  ET(ET_SEQUENCE)  // See SequenceType.
+
+enum ElementaryType {
+  #define FLATBUFFERS_ET(E) E,
+    FLATBUFFERS_GEN_ELEMENTARY_TYPES(FLATBUFFERS_ET)
+  #undef FLATBUFFERS_ET
+};
+
+inline const char * const *ElementaryTypeNames() {
+  static const char * const names[] = {
+    #define FLATBUFFERS_ET(E) #E,
+      FLATBUFFERS_GEN_ELEMENTARY_TYPES(FLATBUFFERS_ET)
+    #undef FLATBUFFERS_ET
+  };
+  return names;
+}
+// clang-format on
+
+// Basic type info cost just 16bits per field!
+struct TypeCode {
+  uint16_t base_type : 4;  // ElementaryType
+  uint16_t is_vector : 1;
+  int16_t sequence_ref : 11;  // Index into type_refs below, or -1 for none.
+};
+
+static_assert(sizeof(TypeCode) == 2, "TypeCode");
+
+struct TypeTable;
+
+// Signature of the static method present in each type.
+typedef const TypeTable *(*TypeFunction)();
+
+struct TypeTable {
+  SequenceType st;
+  size_t num_elems;  // of type_codes, values, names (but not type_refs).
+  const TypeCode *type_codes;     // num_elems count
+  const TypeFunction *type_refs;  // less than num_elems entries (see TypeCode).
+  const int64_t *values;  // Only set for non-consecutive enum/union or structs.
+  const char *const *names;  // Only set if compiled with --reflect-names.
+};
+
+// String which identifies the current version of FlatBuffers.
+// flatbuffer_version_string is used by Google developers to identify which
+// applications uploaded to Google Play are using this library.  This allows
+// the development team at Google to determine the popularity of the library.
+// How it works: Applications that are uploaded to the Google Play Store are
+// scanned for this version string.  We track which applications are using it
+// to measure popularity.  You are free to remove it (of course) but we would
+// appreciate if you left it in.
+
+// Weak linkage is culled by VS & doesn't work on cygwin.
+// clang-format off
+#if !defined(_WIN32) && !defined(__CYGWIN__)
+
+extern volatile __attribute__((weak)) const char *flatbuffer_version_string;
+volatile __attribute__((weak)) const char *flatbuffer_version_string =
+  "FlatBuffers "
+  FLATBUFFERS_STRING(FLATBUFFERS_VERSION_MAJOR) "."
+  FLATBUFFERS_STRING(FLATBUFFERS_VERSION_MINOR) "."
+  FLATBUFFERS_STRING(FLATBUFFERS_VERSION_REVISION);
+
+#endif  // !defined(_WIN32) && !defined(__CYGWIN__)
+
+#define FLATBUFFERS_DEFINE_BITMASK_OPERATORS(E, T)\
+    inline E operator | (E lhs, E rhs){\
+        return E(T(lhs) | T(rhs));\
+    }\
+    inline E operator & (E lhs, E rhs){\
+        return E(T(lhs) & T(rhs));\
+    }\
+    inline E operator ^ (E lhs, E rhs){\
+        return E(T(lhs) ^ T(rhs));\
+    }\
+    inline E operator ~ (E lhs){\
+        return E(~T(lhs));\
+    }\
+    inline E operator |= (E &lhs, E rhs){\
+        lhs = lhs | rhs;\
+        return lhs;\
+    }\
+    inline E operator &= (E &lhs, E rhs){\
+        lhs = lhs & rhs;\
+        return lhs;\
+    }\
+    inline E operator ^= (E &lhs, E rhs){\
+        lhs = lhs ^ rhs;\
+        return lhs;\
+    }\
+    inline bool operator !(E rhs) \
+    {\
+        return !bool(T(rhs)); \
+    }
+/// @endcond
+}  // namespace flatbuffers
+
+// clang-format on
+
+#endif  // FLATBUFFERS_H_
diff --git a/src/arrow/cpp/thirdparty/flatbuffers/include/flatbuffers/stl_emulation.h b/src/arrow/cpp/thirdparty/flatbuffers/include/flatbuffers/stl_emulation.h
new file mode 100644
index 000000000..8bae61bfd
--- /dev/null
+++ b/src/arrow/cpp/thirdparty/flatbuffers/include/flatbuffers/stl_emulation.h
@@ -0,0 +1,307 @@
+/*
+ * Copyright 2017 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef FLATBUFFERS_STL_EMULATION_H_
+#define FLATBUFFERS_STL_EMULATION_H_
+
+// clang-format off
+
+#include <string>
+#include <type_traits>
+#include <vector>
+#include <memory>
+#include <limits>
+
+#if defined(_STLPORT_VERSION) && !defined(FLATBUFFERS_CPP98_STL)
+  #define FLATBUFFERS_CPP98_STL
+#endif  // defined(_STLPORT_VERSION) && !defined(FLATBUFFERS_CPP98_STL)
+
+#if defined(FLATBUFFERS_CPP98_STL)
+  #include <cctype>
+#endif  // defined(FLATBUFFERS_CPP98_STL)
+
+// Check if we can use template aliases
+// Not possible if Microsoft Compiler before 2012
+// Possible is the language feature __cpp_alias_templates is defined well
+// Or possible if the C++ std is C+11 or newer
+#if (defined(_MSC_VER) && _MSC_VER > 1700 /* MSVC2012 */) \
+    || (defined(__cpp_alias_templates) && __cpp_alias_templates >= 200704) \
+    || (defined(__cplusplus) && __cplusplus >= 201103L)
+  #define FLATBUFFERS_TEMPLATES_ALIASES
+#endif
+
+// This header provides backwards compatibility for C++98 STLs like stlport.
+namespace flatbuffers {
+
+// Retrieve ::back() from a string in a way that is compatible with pre C++11
+// STLs (e.g stlport).
+inline char& string_back(std::string &value) {
+  return value[value.length() - 1];
+}
+
+inline char string_back(const std::string &value) {
+  return value[value.length() - 1];
+}
+
+// Helper method that retrieves ::data() from a vector in a way that is
+// compatible with pre C++11 STLs (e.g stlport).
+template <typename T> inline T *vector_data(std::vector<T> &vector) {
+  // In some debug environments, operator[] does bounds checking, so &vector[0]
+  // can't be used.
+  return vector.empty() ? nullptr : &vector[0];
+}
+
+template <typename T> inline const T *vector_data(
+    const std::vector<T> &vector) {
+  return vector.empty() ? nullptr : &vector[0];
+}
+
+template <typename T, typename V>
+inline void vector_emplace_back(std::vector<T> *vector, V &&data) {
+  #if defined(FLATBUFFERS_CPP98_STL)
+    vector->push_back(data);
+  #else
+    vector->emplace_back(std::forward<V>(data));
+  #endif  // defined(FLATBUFFERS_CPP98_STL)
+}
+
+#ifndef FLATBUFFERS_CPP98_STL
+  #if defined(FLATBUFFERS_TEMPLATES_ALIASES)
+    template <typename T>
+    using numeric_limits = std::numeric_limits<T>;
+  #else
+    template <typename T> class numeric_limits :
+      public std::numeric_limits<T> {};
+  #endif  // defined(FLATBUFFERS_TEMPLATES_ALIASES)
+#else
+  template <typename T> class numeric_limits :
+      public std::numeric_limits<T> {
+    public:
+      // Android NDK fix.
+      static T lowest() {
+        return std::numeric_limits<T>::min();
+      }
+  };
+
+  template <> class numeric_limits<float> :
+      public std::numeric_limits<float> {
+    public:
+      static float lowest() { return -FLT_MAX; }
+  };
+
+  template <> class numeric_limits<double> :
+      public std::numeric_limits<double> {
+    public:
+      static double lowest() { return -DBL_MAX; }
+  };
+
+  template <> class numeric_limits<unsigned long long> {
+   public:
+    static unsigned long long min() { return 0ULL; }
+    static unsigned long long max() { return ~0ULL; }
+    static unsigned long long lowest() {
+      return numeric_limits<unsigned long long>::min();
+    }
+  };
+
+  template <> class numeric_limits<long long> {
+   public:
+    static long long min() {
+      return static_cast<long long>(1ULL << ((sizeof(long long) << 3) - 1));
+    }
+    static long long max() {
+      return static_cast<long long>(
+          (1ULL << ((sizeof(long long) << 3) - 1)) - 1);
+    }
+    static long long lowest() {
+      return numeric_limits<long long>::min();
+    }
+  };
+#endif  // FLATBUFFERS_CPP98_STL
+
+#if defined(FLATBUFFERS_TEMPLATES_ALIASES)
+  #ifndef FLATBUFFERS_CPP98_STL
+    template <typename T> using is_scalar = std::is_scalar<T>;
+    template <typename T, typename U> using is_same = std::is_same<T,U>;
+    template <typename T> using is_floating_point = std::is_floating_point<T>;
+    template <typename T> using is_unsigned = std::is_unsigned<T>;
+    template <typename T> using is_enum = std::is_enum<T>;
+    template <typename T> using make_unsigned = std::make_unsigned<T>;
+    template<bool B, class T, class F>
+    using conditional = std::conditional<B, T, F>;
+    template<class T, T v>
+    using integral_constant = std::integral_constant<T, v>;
+  #else
+    // Map C++ TR1 templates defined by stlport.
+    template <typename T> using is_scalar = std::tr1::is_scalar<T>;
+    template <typename T, typename U> using is_same = std::tr1::is_same<T,U>;
+    template <typename T> using is_floating_point =
+        std::tr1::is_floating_point<T>;
+    template <typename T> using is_unsigned = std::tr1::is_unsigned<T>;
+    template <typename T> using is_enum = std::tr1::is_enum<T>;
+    // Android NDK doesn't have std::make_unsigned or std::tr1::make_unsigned.
+    template<typename T> struct make_unsigned {
+      static_assert(is_unsigned<T>::value, "Specialization not implemented!");
+      using type = T;
+    };
+    template<> struct make_unsigned<char> { using type = unsigned char; };
+    template<> struct make_unsigned<short> { using type = unsigned short; };
+    template<> struct make_unsigned<int> { using type = unsigned int; };
+    template<> struct make_unsigned<long> { using type = unsigned long; };
+    template<>
+    struct make_unsigned<long long> { using type = unsigned long long; };
+    template<bool B, class T, class F>
+    using conditional = std::tr1::conditional<B, T, F>;
+    template<class T, T v>
+    using integral_constant = std::tr1::integral_constant<T, v>;
+  #endif  // !FLATBUFFERS_CPP98_STL
+#else
+  // MSVC 2010 doesn't support C++11 aliases.
+  template <typename T> struct is_scalar : public std::is_scalar<T> {};
+  template <typename T, typename U> struct is_same : public std::is_same<T,U> {};
+  template <typename T> struct is_floating_point :
+        public std::is_floating_point<T> {};
+  template <typename T> struct is_unsigned : public std::is_unsigned<T> {};
+  template <typename T> struct is_enum : public std::is_enum<T> {};
+  template <typename T> struct make_unsigned : public std::make_unsigned<T> {};
+  template<bool B, class T, class F>
+  struct conditional : public std::conditional<B, T, F> {};
+  template<class T, T v>
+  struct integral_constant : public std::integral_constant<T, v> {};
+#endif  // defined(FLATBUFFERS_TEMPLATES_ALIASES)
+
+#ifndef FLATBUFFERS_CPP98_STL
+  #if defined(FLATBUFFERS_TEMPLATES_ALIASES)
+    template <class T> using unique_ptr = std::unique_ptr<T>;
+  #else
+    // MSVC 2010 doesn't support C++11 aliases.
+    // We're manually "aliasing" the class here as we want to bring unique_ptr
+    // into the flatbuffers namespace.  We have unique_ptr in the flatbuffers
+    // namespace we have a completely independent implemenation (see below)
+    // for C++98 STL implementations.
+    template <class T> class unique_ptr : public std::unique_ptr<T> {
+     public:
+      unique_ptr() {}
+      explicit unique_ptr(T* p) : std::unique_ptr<T>(p) {}
+      unique_ptr(std::unique_ptr<T>&& u) { *this = std::move(u); }
+      unique_ptr(unique_ptr&& u) { *this = std::move(u); }
+      unique_ptr& operator=(std::unique_ptr<T>&& u) {
+        std::unique_ptr<T>::reset(u.release());
+        return *this;
+      }
+      unique_ptr& operator=(unique_ptr&& u) {
+        std::unique_ptr<T>::reset(u.release());
+        return *this;
+      }
+      unique_ptr& operator=(T* p) {
+        return std::unique_ptr<T>::operator=(p);
+      }
+    };
+  #endif  // defined(FLATBUFFERS_TEMPLATES_ALIASES)
+#else
+  // Very limited implementation of unique_ptr.
+  // This is provided simply to allow the C++ code generated from the default
+  // settings to function in C++98 environments with no modifications.
+  template <class T> class unique_ptr {
+   public:
+    typedef T element_type;
+
+    unique_ptr() : ptr_(nullptr) {}
+    explicit unique_ptr(T* p) : ptr_(p) {}
+    unique_ptr(unique_ptr&& u) : ptr_(nullptr) { reset(u.release()); }
+    unique_ptr(const unique_ptr& u) : ptr_(nullptr) {
+      reset(const_cast<unique_ptr*>(&u)->release());
+    }
+    ~unique_ptr() { reset(); }
+
+    unique_ptr& operator=(const unique_ptr& u) {
+      reset(const_cast<unique_ptr*>(&u)->release());
+      return *this;
+    }
+
+    unique_ptr& operator=(unique_ptr&& u) {
+      reset(u.release());
+      return *this;
+    }
+
+    unique_ptr& operator=(T* p) {
+      reset(p);
+      return *this;
+    }
+
+    const T& operator*() const { return *ptr_; }
+    T* operator->() const { return ptr_; }
+    T* get() const noexcept { return ptr_; }
+    explicit operator bool() const { return ptr_ != nullptr; }
+
+    // modifiers
+    T* release() {
+      T* value = ptr_;
+      ptr_ = nullptr;
+      return value;
+    }
+
+    void reset(T* p = nullptr) {
+      T* value = ptr_;
+      ptr_ = p;
+      if (value) delete value;
+    }
+
+    void swap(unique_ptr& u) {
+      T* temp_ptr = ptr_;
+      ptr_ = u.ptr_;
+      u.ptr_ = temp_ptr;
+    }
+
+   private:
+    T* ptr_;
+  };
+
+  template <class T> bool operator==(const unique_ptr<T>& x,
+                                     const unique_ptr<T>& y) {
+    return x.get() == y.get();
+  }
+
+  template <class T, class D> bool operator==(const unique_ptr<T>& x,
+                                              const D* y) {
+    return static_cast<D*>(x.get()) == y;
+  }
+
+  template <class T> bool operator==(const unique_ptr<T>& x, intptr_t y) {
+    return reinterpret_cast<intptr_t>(x.get()) == y;
+  }
+
+  template <class T> bool operator!=(const unique_ptr<T>& x, decltype(nullptr)) {
+    return !!x;
+  }
+
+  template <class T> bool operator!=(decltype(nullptr), const unique_ptr<T>& x) {
+    return !!x;
+  }
+
+  template <class T> bool operator==(const unique_ptr<T>& x, decltype(nullptr)) {
+    return !x;
+  }
+
+  template <class T> bool operator==(decltype(nullptr), const unique_ptr<T>& x) {
+    return !x;
+  }
+
+#endif  // !FLATBUFFERS_CPP98_STL
+
+}  // namespace flatbuffers
+
+#endif  // FLATBUFFERS_STL_EMULATION_H_