README.md
In arrow: Integration to 'Apache' 'Arrow'

This directory contains a vendored version of Flatbuffers (unknown changeset), with two patches: the first patch for ARROW-15388 and the second patch for ARROW-17280.

diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/base.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/base.h
index 955738067..fccce42f6 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/base.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/base.h
@@ -212,13 +212,6 @@ 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

diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/base.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/base.h
index fccce42f6..a00d5b0fd 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/base.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/base.h
@@ -1,6 +1,14 @@
 #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 {
+namespace flatbuffers {
+}
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
 // clang-format off

 // If activate should be declared and included first.
@@ -144,10 +152,12 @@
 #define FLATBUFFERS_VERSION_REVISION 0
 #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)) || \
@@ -201,16 +211,20 @@ 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 arrow_vendored_private {
       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 arrow_vendored_private {
       namespace flatbuffers {
         typedef std::experimental::string_view string_view;
       }
+      }
       #define FLATBUFFERS_HAS_STRING_VIEW 1
     #endif
   #endif // __has_include
@@ -278,6 +292,7 @@ template<typename T> FLATBUFFERS_CONSTEXPR inline bool IsConstTrue(T t) {
 /// @endcond

 /// @file
+namespace arrow_vendored_private {
 namespace flatbuffers {

 /// @cond FLATBUFFERS_INTERNAL
@@ -388,4 +403,5 @@ inline size_t PaddingBytes(size_t buf_size, size_t scalar_size) {
 }

 }  // namespace flatbuffers
+}  // namespace arrow_vendored_private
 #endif  // FLATBUFFERS_BASE_H_
diff --git a/cpp/thirdparty/flatbuffers/include/flatbuffers/flatbuffers.h b/cpp/thirdparty/flatbuffers/include/flatbuffers/flatbuffers.h
index c4dc5bcd0..2f7eb5fcf 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/flatbuffers.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/flatbuffers.h
@@ -23,6 +23,15 @@
 #  include <cmath>
 #endif

+// Move this vendored copy of flatbuffers to a private namespace,
+// but continue to access it through the "flatbuffers" alias.
+namespace arrow_vendored_private {
+namespace flatbuffers {
+}
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
+namespace arrow_vendored_private {
 namespace flatbuffers {
 // Generic 'operator==' with conditional specialisations.
 // T e - new value of a scalar field.
@@ -2777,6 +2786,7 @@ volatile __attribute__((weak)) const char *flatbuffer_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 8bae61bfd..7e5a95233 100644
--- a/cpp/thirdparty/flatbuffers/include/flatbuffers/stl_emulation.h
+++ b/cpp/thirdparty/flatbuffers/include/flatbuffers/stl_emulation.h
@@ -25,6 +25,14 @@
 #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 {
+namespace flatbuffers {
+}
+}
+namespace flatbuffers = arrow_vendored_private::flatbuffers;
+
 #if defined(_STLPORT_VERSION) && !defined(FLATBUFFERS_CPP98_STL)
   #define FLATBUFFERS_CPP98_STL
 #endif  // defined(_STLPORT_VERSION) && !defined(FLATBUFFERS_CPP98_STL)
@@ -44,6 +52,7 @@
 #endif

 // This header provides backwards compatibility for C++98 STLs like stlport.
+namespace arrow_vendored_private {
 namespace flatbuffers {

 // Retrieve ::back() from a string in a way that is compatible with pre C++11
@@ -303,5 +312,6 @@ inline void vector_emplace_back(std::vector<T> *vector, V &&data) {
 #endif  // !FLATBUFFERS_CPP98_STL

 }  // namespace flatbuffers
+}  // namespace arrow_vendored_private

 #endif  // FLATBUFFERS_STL_EMULATION_H_
-- 
2.25.1