This is a minimal amount of #ifdef's to make stlport work.

Minimal, in the sense that this will only allow flatbuffers.h +
generated code to work. Everything else (tests, parsing, reflection
etc.) may still not compile with stlport.

Functionality has been reduced, some utility functions are not
available.

Tested: on Linux (no stlport), Android (stlport).

Change-Id: I3f8b6a88258c07d78964dd455fb9f99f65266301

include/flatbuffers/flatbuffers.h

@@ -24,13 +24,20 @@
 #include <cstdlib>
 #include <cstring>
 #include <string>
+#include <utility>
 #include <type_traits>
 #include <vector>
 #include <set>
 #include <algorithm>
-#include <functional>
 #include <memory>
 
+#ifdef _STLPORT_VERSION
+  #define FLATBUFFERS_CPP98_STL
+#endif
+#ifndef FLATBUFFERS_CPP98_STL
+  #include <functional>
+#endif
+
 /// @cond FLATBUFFERS_INTERNAL
 #if __cplusplus <= 199711L && \
     (!defined(_MSC_VER) || _MSC_VER < 1600) && \
@@ -123,9 +130,11 @@ typedef uintmax_t largest_scalar_t;
 // In 32bits, this evaluates to 2GB - 1
 #define FLATBUFFERS_MAX_BUFFER_SIZE ((1ULL << (sizeof(soffset_t) * 8 - 1)) - 1)
 
+#ifndef FLATBUFFERS_CPP98_STL
 // Pointer to relinquished memory.
 typedef std::unique_ptr<uint8_t, std::function<void(uint8_t * /* unused */)>>
           unique_ptr_t;
+#endif
 
 // Wrapper for uoffset_t to allow safe template specialization.
 template<typename T> struct Offset {
@@ -234,23 +243,19 @@ template<typename T> struct IndirectHelper<const T *> {
 
 // An STL compatible iterator implementation for Vector below, effectively
 // calling Get() for every element.
-template<typename T, bool bConst>
-struct VectorIterator : public
-  std::iterator < std::input_iterator_tag,
-  typename std::conditional < bConst,
-  const typename IndirectHelper<T>::return_type,
-  typename IndirectHelper<T>::return_type > ::type, uoffset_t > {
-
-  typedef std::iterator<std::input_iterator_tag,
-    typename std::conditional<bConst,
-    const typename IndirectHelper<T>::return_type,
-    typename IndirectHelper<T>::return_type>::type, uoffset_t> super_type;
+template<typename T, typename IT>
+struct VectorIterator
+    : public std::iterator<std::input_iterator_tag, IT, uoffset_t> {
+
+  typedef std::iterator<std::input_iterator_tag, IT, uoffset_t> super_type;
 
 public:
   VectorIterator(const uint8_t *data, uoffset_t i) :
       data_(data + IndirectHelper<T>::element_stride * i) {};
   VectorIterator(const VectorIterator &other) : data_(other.data_) {}
+  #ifndef FLATBUFFERS_CPP98_STL
   VectorIterator(VectorIterator &&other) : data_(std::move(other.data_)) {}
+  #endif
 
   VectorIterator &operator=(const VectorIterator &other) {
     data_ = other.data_;
@@ -301,8 +306,10 @@ private:
 // Vector::data() assumes the vector elements start after the length field.
 template<typename T> class Vector {
 public:
-  typedef VectorIterator<T, false> iterator;
-  typedef VectorIterator<T, true> const_iterator;
+  typedef VectorIterator<T, typename IndirectHelper<T>::mutable_return_type>
+    iterator;
+  typedef VectorIterator<T, typename IndirectHelper<T>::return_type>
+    const_iterator;
 
   uoffset_t size() const { return EndianScalar(length_); }
 
@@ -471,6 +478,7 @@ class vector_downward {
     cur_ = buf_ + reserved_;
   }
 
+  #ifndef FLATBUFFERS_CPP98_STL
   // Relinquish the pointer to the caller.
   unique_ptr_t release() {
     // Actually deallocate from the start of the allocated memory.
@@ -486,6 +494,7 @@ class vector_downward {
 
     return retval;
   }
+  #endif
 
   size_t growth_policy(size_t bytes) {
     return (bytes / 2) & ~(sizeof(largest_scalar_t) - 1);
@@ -562,6 +571,10 @@ inline voffset_t FieldIndexToOffset(voffset_t field_id) {
 inline size_t PaddingBytes(size_t buf_size, size_t scalar_size) {
   return ((~buf_size) + 1) & (scalar_size - 1);
 }
+
+template <typename T> const T* data(const std::vector<T> &v) {
+  return v.empty() ? nullptr : &v.front();
+}
 /// @endcond
 
 /// @addtogroup flatbuffers_cpp_api
@@ -627,6 +640,7 @@ FLATBUFFERS_FINAL_CLASS
   /// @return Returns a `uint8_t` pointer to the unfinished buffer.
   uint8_t *GetCurrentBufferPointer() const { return buf_.data(); }
 
+  #ifndef FLATBUFFERS_CPP98_STL
   /// @brief Get the released pointer to the serialized buffer.
   /// @warning Do NOT attempt to use this FlatBufferBuilder afterwards!
   /// @return The `unique_ptr` returned has a special allocator that knows how
@@ -637,6 +651,7 @@ FLATBUFFERS_FINAL_CLASS
     Finished();
     return buf_.release();
   }
+  #endif
 
   /// @cond FLATBUFFERS_INTERNAL
   void Finished() const {
@@ -674,11 +689,13 @@ FLATBUFFERS_FINAL_CLASS
   void PopBytes(size_t amount) { buf_.pop(amount); }
 
   template<typename T> void AssertScalarT() {
+    #ifndef FLATBUFFERS_CPP98_STL
     // The code assumes power of 2 sizes and endian-swap-ability.
     static_assert(std::is_scalar<T>::value
         // The Offset<T> type is essentially a scalar but fails is_scalar.
         || sizeof(T) == sizeof(Offset<void>),
            "T must be a scalar type");
+    #endif
   }
 
   // Write a single aligned scalar to the buffer
@@ -981,7 +998,7 @@ FLATBUFFERS_FINAL_CLASS
   /// @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(v.data(), v.size());
+    return CreateVector(data(v), v.size());
   }
 
   // vector<bool> may be implemented using a bit-set, so we can't access it as
@@ -995,6 +1012,7 @@ FLATBUFFERS_FINAL_CLASS
     return Offset<Vector<uint8_t>>(EndVector(v.size()));
   }
 
+  #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.
@@ -1006,8 +1024,9 @@ FLATBUFFERS_FINAL_CLASS
       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.data(), elems.size());
+    return CreateVector(elems);
   }
+  #endif
 
   /// @brief Serialize a `std::vector<std::string>` into a FlatBuffer `vector`.
   /// This is a convenience function for a common case.
@@ -1019,7 +1038,7 @@ FLATBUFFERS_FINAL_CLASS
       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.data(), offsets.size());
+    return CreateVector(offsets);
   }
 
   /// @brief Serialize an array of structs into a FlatBuffer `vector`.
@@ -1044,7 +1063,7 @@ FLATBUFFERS_FINAL_CLASS
   /// where the vector is stored.
   template<typename T> Offset<Vector<const T *>> CreateVectorOfStructs(
       const std::vector<T> &v) {
-    return CreateVectorOfStructs(v.data(), v.size());
+    return CreateVectorOfStructs(data(v), v.size());
   }
 
   /// @cond FLATBUFFERS_INTERNAL

include/flatbuffers/reflection.h

@@ -370,6 +370,7 @@ uint8_t *ResizeAnyVector(const reflection::Schema &schema, uoffset_t newsize,
                          uoffset_t elem_size, std::vector<uint8_t> *flatbuf,
                          const reflection::Object *root_table = nullptr);
 
+#ifndef FLATBUFFERS_CPP98_STL
 template <typename T>
 void ResizeVector(const reflection::Schema &schema, uoffset_t newsize, T val,
                   const Vector<T> *vec, std::vector<uint8_t> *flatbuf,
@@ -391,6 +392,7 @@ void ResizeVector(const reflection::Schema &schema, uoffset_t newsize, T val,
     }
   }
 }
+#endif
 
 // Adds any new data (in the form of a new FlatBuffer) to an existing
 // FlatBuffer. This can be used when any of the above methods are not

tests/test.cpp

@@ -25,7 +25,9 @@
 #include "namespace_test/namespace_test1_generated.h"
 #include "namespace_test/namespace_test2_generated.h"
 
-#include <random>
+#ifndef FLATBUFFERS_CPP98_STL
+  #include <random>
+#endif
 
 using namespace MyGame::Example;