This directory contains a vendored version of Flatbuffers (v24.3.6), with a patch for ARROW-17280.

diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/allocator.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/allocator.h
index 30427190b..f0e91d0a3 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/allocator.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/allocator.h
@@ -17,9 +17,15 @@
 #ifndef FLATBUFFERS_ALLOCATOR_H_
 #define FLATBUFFERS_ALLOCATOR_H_
 
+// Move this vendored copy of flatbuffers to a private namespace,
+// but continue to access it through the "flatbuffers" alias.
+namespace arrow_vendored_private::flatbuffers {
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
 #include "flatbuffers/base.h"
 
-namespace flatbuffers {
+namespace arrow_vendored_private::flatbuffers {
 
 // Allocator interface. This is flatbuffers-specific and meant only for
 // `vector_downward` usage.
@@ -63,6 +69,6 @@ class Allocator {
   }
 };
 
-}  // namespace flatbuffers
+}  // namespace arrow_vendored_private
 
 #endif  // FLATBUFFERS_ALLOCATOR_H_
diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/array.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/array.h
index f4bfbf054..f8e78243a 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/array.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/array.h
@@ -17,6 +17,12 @@
 #ifndef FLATBUFFERS_ARRAY_H_
 #define FLATBUFFERS_ARRAY_H_
 
+// Move this vendored copy of flatbuffers to a private namespace,
+// but continue to access it through the "flatbuffers" alias.
+namespace arrow_vendored_private::flatbuffers {
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
 #include <cstdint>
 #include <memory>
 
@@ -24,7 +30,7 @@
 #include "flatbuffers/stl_emulation.h"
 #include "flatbuffers/vector.h"
 
-namespace flatbuffers {
+namespace arrow_vendored_private::flatbuffers {
 
 // This is used as a helper type for accessing arrays.
 template<typename T, uint16_t length> class Array {
@@ -251,6 +257,6 @@ bool operator==(const Array<T, length> &lhs,
           std::memcmp(lhs.Data(), rhs.Data(), rhs.size() * sizeof(T)) == 0);
 }
 
-}  // namespace flatbuffers
+}  // namespace arrow_vendored_private
 
 #endif  // FLATBUFFERS_ARRAY_H_
diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/base.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/base.h
index 5c4cae791..1b0c7d987 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/base.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/base.h
@@ -1,6 +1,12 @@
 #ifndef FLATBUFFERS_BASE_H_
 #define FLATBUFFERS_BASE_H_
 
+// Move this vendored copy of flatbuffers to a private namespace,
+// but continue to access it through the "flatbuffers" alias.
+namespace arrow_vendored_private::flatbuffers {
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
 // clang-format off
 
 // If activate should be declared and included first.
@@ -144,10 +150,13 @@
 #define FLATBUFFERS_VERSION_REVISION 26
 #define FLATBUFFERS_STRING_EXPAND(X) #X
 #define FLATBUFFERS_STRING(X) FLATBUFFERS_STRING_EXPAND(X)
+
+namespace arrow_vendored_private {
 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)) || \
@@ -222,14 +231,14 @@ namespace flatbuffers {
     // 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 {
+      namespace arrow_vendored_private::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 {
+      namespace arrow_vendored_private::flatbuffers {
         typedef std::experimental::string_view string_view;
       }
       #define FLATBUFFERS_HAS_STRING_VIEW 1
@@ -240,7 +249,7 @@ namespace flatbuffers {
       #include "absl/base/config.h"
       #if !defined(ABSL_USES_STD_STRING_VIEW)
         #include "absl/strings/string_view.h"
-        namespace flatbuffers {
+        namespace arrow_vendored_private::flatbuffers {
           typedef absl::string_view string_view;
         }
         #define FLATBUFFERS_HAS_STRING_VIEW 1
@@ -317,6 +326,7 @@ template<typename T> FLATBUFFERS_CONSTEXPR inline bool IsConstTrue(T t) {
 /// @endcond
 
 /// @file
+namespace arrow_vendored_private {
 namespace flatbuffers {
 
 /// @cond FLATBUFFERS_INTERNAL
@@ -492,4 +502,6 @@ inline bool IsInRange(const T &v, const T &low, const T &high) {
 }
 
 }  // namespace flatbuffers
+}  // namespace arrow_vendored_private
+
 #endif  // FLATBUFFERS_BASE_H_
diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/buffer.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/buffer.h
index 94d4f7903..e791c3007 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/buffer.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/buffer.h
@@ -17,11 +17,17 @@
 #ifndef FLATBUFFERS_BUFFER_H_
 #define FLATBUFFERS_BUFFER_H_
 
+// Move this vendored copy of flatbuffers to a private namespace,
+// but continue to access it through the "flatbuffers" alias.
+namespace arrow_vendored_private::flatbuffers {
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
 #include <algorithm>
 
 #include "flatbuffers/base.h"
 
-namespace flatbuffers {
+namespace arrow_vendored_private::flatbuffers {
 
 // Wrapper for uoffset_t to allow safe template specialization.
 // Value is allowed to be 0 to indicate a null object (see e.g. AddOffset).
@@ -194,6 +200,6 @@ const T *GetSizePrefixedRoot(const void *buf) {
   return GetRoot<T>(reinterpret_cast<const uint8_t *>(buf) + sizeof(SizeT));
 }
 
-}  // namespace flatbuffers
+}  // namespace arrow_vendored_private
 
 #endif  // FLATBUFFERS_BUFFER_H_
diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/buffer_ref.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/buffer_ref.h
index f70941fc6..8a4a43f81 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/buffer_ref.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/buffer_ref.h
@@ -17,10 +17,16 @@
 #ifndef FLATBUFFERS_BUFFER_REF_H_
 #define FLATBUFFERS_BUFFER_REF_H_
 
+// Move this vendored copy of flatbuffers to a private namespace,
+// but continue to access it through the "flatbuffers" alias.
+namespace arrow_vendored_private::flatbuffers {
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
 #include "flatbuffers/base.h"
 #include "flatbuffers/verifier.h"
 
-namespace flatbuffers {
+namespace arrow_vendored_private::flatbuffers {
 
 // Convenient way to bundle a buffer and its length, to pass it around
 // typed by its root.
@@ -48,6 +54,6 @@ template<typename T> struct BufferRef : BufferRefBase {
   bool must_free;
 };
 
-}  // namespace flatbuffers
+}  // namespace arrow_vendored_private
 
 #endif  // FLATBUFFERS_BUFFER_REF_H_
diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/default_allocator.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/default_allocator.h
index d4724122c..fd2dc60a9 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/default_allocator.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/default_allocator.h
@@ -17,10 +17,16 @@
 #ifndef FLATBUFFERS_DEFAULT_ALLOCATOR_H_
 #define FLATBUFFERS_DEFAULT_ALLOCATOR_H_
 
+// Move this vendored copy of flatbuffers to a private namespace,
+// but continue to access it through the "flatbuffers" alias.
+namespace arrow_vendored_private::flatbuffers {
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
 #include "flatbuffers/allocator.h"
 #include "flatbuffers/base.h"
 
-namespace flatbuffers {
+namespace arrow_vendored_private::flatbuffers {
 
 // DefaultAllocator uses new/delete to allocate memory regions
 class DefaultAllocator : public Allocator {
@@ -59,6 +65,6 @@ inline uint8_t *ReallocateDownward(Allocator *allocator, uint8_t *old_p,
                          old_p, old_size, new_size, in_use_back, in_use_front);
 }
 
-}  // namespace flatbuffers
+}  // namespace arrow_vendored_private
 
 #endif  // FLATBUFFERS_DEFAULT_ALLOCATOR_H_
diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/detached_buffer.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/detached_buffer.h
index 5e900baeb..4779545b3 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/detached_buffer.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/detached_buffer.h
@@ -17,11 +17,17 @@
 #ifndef FLATBUFFERS_DETACHED_BUFFER_H_
 #define FLATBUFFERS_DETACHED_BUFFER_H_
 
+// Move this vendored copy of flatbuffers to a private namespace,
+// but continue to access it through the "flatbuffers" alias.
+namespace arrow_vendored_private::flatbuffers {
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
 #include "flatbuffers/allocator.h"
 #include "flatbuffers/base.h"
 #include "flatbuffers/default_allocator.h"
 
-namespace flatbuffers {
+namespace arrow_vendored_private::flatbuffers {
 
 // DetachedBuffer is a finished flatbuffer memory region, detached from its
 // builder. The original memory region and allocator are also stored so that
@@ -109,6 +115,6 @@ class DetachedBuffer {
   }
 };
 
-}  // namespace flatbuffers
+}  // namespace arrow_vendored_private
 
 #endif  // FLATBUFFERS_DETACHED_BUFFER_H_
diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/flatbuffer_builder.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/flatbuffer_builder.h
index 0a38b4ac3..5825cc05c 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/flatbuffer_builder.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/flatbuffer_builder.h
@@ -17,6 +17,12 @@
 #ifndef FLATBUFFERS_FLATBUFFER_BUILDER_H_
 #define FLATBUFFERS_FLATBUFFER_BUILDER_H_
 
+// Move this vendored copy of flatbuffers to a private namespace,
+// but continue to access it through the "flatbuffers" alias.
+namespace arrow_vendored_private::flatbuffers {
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
 #include <algorithm>
 #include <cstdint>
 #include <functional>
@@ -38,6 +44,7 @@
 #include "flatbuffers/vector_downward.h"
 #include "flatbuffers/verifier.h"
 
+namespace arrow_vendored_private {
 namespace flatbuffers {
 
 // Converts a Field ID to a virtual table offset.
@@ -1461,5 +1468,6 @@ const T *GetTemporaryPointer(FlatBufferBuilder &fbb, Offset<T> offset) {
 }
 
 }  // namespace flatbuffers
+}  // namespace arrow_vendored_private
 
 #endif  // FLATBUFFERS_FLATBUFFER_BUILDER_H_
diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/flatbuffers.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/flatbuffers.h
index bc828a313..8aa19a65c 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/flatbuffers.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/flatbuffers.h
@@ -17,6 +17,12 @@
 #ifndef FLATBUFFERS_H_
 #define FLATBUFFERS_H_
 
+// Move this vendored copy of flatbuffers to a private namespace,
+// but continue to access it through the "flatbuffers" alias.
+namespace arrow_vendored_private::flatbuffers {
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
 #include <algorithm>
 
 // TODO: These includes are for mitigating the pains of users editing their
@@ -35,6 +41,7 @@
 #include "flatbuffers/vector_downward.h"
 #include "flatbuffers/verifier.h"
 
+namespace arrow_vendored_private {
 namespace flatbuffers {
 
 /// @brief This can compute the start of a FlatBuffer from a root pointer, i.e.
@@ -278,6 +285,7 @@ inline const char *flatbuffers_version_string() {
     }
 /// @endcond
 }  // namespace flatbuffers
+}  // namespace arrow_vendored_private
 
 // clang-format on
 
diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/stl_emulation.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/stl_emulation.h
index fd3a8cda7..dcbe23347 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/stl_emulation.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/stl_emulation.h
@@ -26,6 +26,12 @@
 #include <memory>
 #include <limits>
 
+// Move this vendored copy of flatbuffers to a private namespace,
+// but continue to access it through the "flatbuffers" alias.
+namespace arrow_vendored_private::flatbuffers {
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
 #ifndef FLATBUFFERS_USE_STD_OPTIONAL
   // Detect C++17 compatible compiler.
   // __cplusplus >= 201703L - a compiler has support of 'static inline' variables.
@@ -64,6 +70,7 @@
 #endif // defined(FLATBUFFERS_USE_STD_SPAN)
 
 // This header provides backwards compatibility for older versions of the STL.
+namespace arrow_vendored_private {
 namespace flatbuffers {
 
 #if defined(FLATBUFFERS_TEMPLATES_ALIASES)
@@ -509,5 +516,6 @@ flatbuffers::span<const ElementType, dynamic_extent> make_span(const ElementType
 #endif // !defined(FLATBUFFERS_SPAN_MINIMAL)
 
 }  // namespace flatbuffers
+}  // namespace arrow_vendored_private
 
 #endif  // FLATBUFFERS_STL_EMULATION_H_
diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/string.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/string.h
index 97e399fd6..1cdba4588 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/string.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/string.h
@@ -17,9 +17,16 @@
 #ifndef FLATBUFFERS_STRING_H_
 #define FLATBUFFERS_STRING_H_
 
+// Move this vendored copy of flatbuffers to a private namespace,
+// but continue to access it through the "flatbuffers" alias.
+namespace arrow_vendored_private::flatbuffers {
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
 #include "flatbuffers/base.h"
 #include "flatbuffers/vector.h"
 
+namespace arrow_vendored_private {
 namespace flatbuffers {
 
 struct String : public Vector<char> {
@@ -60,5 +67,6 @@ static inline flatbuffers::string_view GetStringView(const String *str) {
 #endif  // FLATBUFFERS_HAS_STRING_VIEW
 
 }  // namespace flatbuffers
+}  // namespace arrow_vendored_private
 
 #endif  // FLATBUFFERS_STRING_H_
diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/struct.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/struct.h
index abacc8a9a..92a8e80bf 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/struct.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/struct.h
@@ -17,8 +17,15 @@
 #ifndef FLATBUFFERS_STRUCT_H_
 #define FLATBUFFERS_STRUCT_H_
 
+// Move this vendored copy of flatbuffers to a private namespace,
+// but continue to access it through the "flatbuffers" alias.
+namespace arrow_vendored_private::flatbuffers {
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
 #include "flatbuffers/base.h"
 
+namespace arrow_vendored_private {
 namespace flatbuffers {
 
 // "structs" are flat structures that do not have an offset table, thus
@@ -49,5 +56,6 @@ class Struct FLATBUFFERS_FINAL_CLASS {
 };
 
 }  // namespace flatbuffers
+}  // namespace arrow_vendored_private
 
 #endif  // FLATBUFFERS_STRUCT_H_
diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/table.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/table.h
index e92d8ae8e..762563daf 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/table.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/table.h
@@ -17,9 +17,16 @@
 #ifndef FLATBUFFERS_TABLE_H_
 #define FLATBUFFERS_TABLE_H_
 
+// Move this vendored copy of flatbuffers to a private namespace,
+// but continue to access it through the "flatbuffers" alias.
+namespace arrow_vendored_private::flatbuffers {
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
 #include "flatbuffers/base.h"
 #include "flatbuffers/verifier.h"
 
+namespace arrow_vendored_private {
 namespace flatbuffers {
 
 // "tables" use an offset table (possibly shared) that allows fields to be
@@ -184,5 +191,6 @@ inline flatbuffers::Optional<bool> Table::GetOptional<uint8_t, bool>(
 }
 
 }  // namespace flatbuffers
+}  // namespace arrow_vendored_private
 
 #endif  // FLATBUFFERS_TABLE_H_
diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/vector.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/vector.h
index ae52b9382..94591859a 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/vector.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/vector.h
@@ -17,10 +17,17 @@
 #ifndef FLATBUFFERS_VECTOR_H_
 #define FLATBUFFERS_VECTOR_H_
 
+// Move this vendored copy of flatbuffers to a private namespace,
+// but continue to access it through the "flatbuffers" alias.
+namespace arrow_vendored_private::flatbuffers {
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
 #include "flatbuffers/base.h"
 #include "flatbuffers/buffer.h"
 #include "flatbuffers/stl_emulation.h"
 
+namespace arrow_vendored_private {
 namespace flatbuffers {
 
 struct String;
@@ -393,5 +400,6 @@ template<typename T> static inline size_t VectorLength(const Vector<T> *v) {
 }
 
 }  // namespace flatbuffers
+}  // namespace arrow_vendored_private
 
 #endif  // FLATBUFFERS_VERIFIER_H_
diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/vector_downward.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/vector_downward.h
index 2b5a92cf1..a87b17b66 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/vector_downward.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/vector_downward.h
@@ -17,6 +17,12 @@
 #ifndef FLATBUFFERS_VECTOR_DOWNWARD_H_
 #define FLATBUFFERS_VECTOR_DOWNWARD_H_
 
+// Move this vendored copy of flatbuffers to a private namespace,
+// but continue to access it through the "flatbuffers" alias.
+namespace arrow_vendored_private::flatbuffers {
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
 #include <algorithm>
 #include <cstdint>
 
@@ -24,6 +30,7 @@
 #include "flatbuffers/default_allocator.h"
 #include "flatbuffers/detached_buffer.h"
 
+namespace arrow_vendored_private {
 namespace flatbuffers {
 
 // This is a minimal replication of std::vector<uint8_t> functionality,
@@ -285,5 +292,6 @@ template<typename SizeT = uoffset_t> class vector_downward {
 };
 
 }  // namespace flatbuffers
+}  // namespace arrow_vendored_private
 
 #endif  // FLATBUFFERS_VECTOR_DOWNWARD_H_
diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/verifier.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/verifier.h
index de1146be9..f6f5ac7f2 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/verifier.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/verifier.h
@@ -17,9 +17,16 @@
 #ifndef FLATBUFFERS_VERIFIER_H_
 #define FLATBUFFERS_VERIFIER_H_
 
+// Move this vendored copy of flatbuffers to a private namespace,
+// but continue to access it through the "flatbuffers" alias.
+namespace arrow_vendored_private::flatbuffers {
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
 #include "flatbuffers/base.h"
 #include "flatbuffers/vector.h"
 
+namespace arrow_vendored_private {
 namespace flatbuffers {
 
 // Helper class to verify the integrity of a FlatBuffer
@@ -328,5 +335,6 @@ inline size_t Verifier::VerifyOffset<uoffset64_t>(const size_t start) const {
 }
 
 }  // namespace flatbuffers
+}  // namespace arrow_vendored_private
 
 #endif  // FLATBUFFERS_VERIFIER_H_
-- 
2.34.1