1// -*- C++ -*- 2//===--------------------------- __nullptr --------------------------------===// 3// 4// The LLVM Compiler Infrastructure 5// 6// This file is dual licensed under the MIT and the University of Illinois Open 7// Source Licenses. See LICENSE.TXT for details. 8// 9//===----------------------------------------------------------------------===// 10 11#ifndef _LIBCPP_NULLPTR 12#define _LIBCPP_NULLPTR 13 14#include <__config> 15 16#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 17#pragma GCC system_header 18#endif 19 20#ifdef _LIBCPP_HAS_NO_NULLPTR 21 22_LIBCPP_BEGIN_NAMESPACE_STD 23 24struct _LIBCPP_TEMPLATE_VIS nullptr_t 25{ 26 void* __lx; 27 28 struct __nat {int __for_bool_;}; 29 30 _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR nullptr_t() : __lx(0) {} 31 _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR nullptr_t(int __nat::*) : __lx(0) {} 32 33 _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR operator int __nat::*() const {return 0;} 34 35 template <class _Tp> 36 _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR 37 operator _Tp* () const {return 0;} 38 39 template <class _Tp, class _Up> 40 _LIBCPP_ALWAYS_INLINE 41 operator _Tp _Up::* () const {return 0;} 42 43 friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator==(nullptr_t, nullptr_t) {return true;} 44 friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator!=(nullptr_t, nullptr_t) {return false;} 45}; 46 47inline _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR nullptr_t __get_nullptr_t() {return nullptr_t(0);} 48 49#define nullptr _VSTD::__get_nullptr_t() 50 51_LIBCPP_END_NAMESPACE_STD 52 53#else // _LIBCPP_HAS_NO_NULLPTR 54 55namespace std 56{ 57 typedef decltype(nullptr) nullptr_t; 58} 59 60#endif // _LIBCPP_HAS_NO_NULLPTR 61 62#endif // _LIBCPP_NULLPTR 63