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/*
* 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_