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 24 struct _LIBCPP_TYPE_VIS_ONLY 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 friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator<(nullptr_t, nullptr_t) {return false;} 46 friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator<=(nullptr_t, nullptr_t) {return true;} 47 friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator>(nullptr_t, nullptr_t) {return false;} 48 friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator>=(nullptr_t, nullptr_t) {return true;} 49 }; 50 51 inline _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR nullptr_t __get_nullptr_t() {return nullptr_t(0);} 52 53 #define nullptr _VSTD::__get_nullptr_t() 54 55 _LIBCPP_END_NAMESPACE_STD 56 57 #else // _LIBCPP_HAS_NO_NULLPTR 58 59 namespace std 60 { 61 typedef decltype(nullptr) nullptr_t; 62 } 63 64 #endif // _LIBCPP_HAS_NO_NULLPTR 65 66 #endif // _LIBCPP_NULLPTR 67
