2 //===--------------------------- __nullptr --------------------------------===//
4 // The LLVM Compiler Infrastructure
6 // This file is dual licensed under the MIT and the University of Illinois Open
7 // Source Licenses. See LICENSE.TXT for details.
9 //===----------------------------------------------------------------------===//
11 #ifndef _LIBCPP_NULLPTR
12 #define _LIBCPP_NULLPTR
16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
17 #pragma GCC system_header
20 #ifdef _LIBCPP_HAS_NO_NULLPTR
22 _LIBCPP_BEGIN_NAMESPACE_STD
24 struct _LIBCPP_TEMPLATE_VIS nullptr_t
28 struct __nat {int __for_bool_;};
30 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR nullptr_t() : __lx(0) {}
31 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR nullptr_t(int __nat::*) : __lx(0) {}
33 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR operator int __nat::*() const {return 0;}
36 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
37 operator _Tp* () const {return 0;}
39 template <class _Tp, class _Up>
40 _LIBCPP_INLINE_VISIBILITY
41 operator _Tp _Up::* () const {return 0;}
43 friend _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR bool operator==(nullptr_t, nullptr_t) {return true;}
44 friend _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR bool operator!=(nullptr_t, nullptr_t) {return false;}
47 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR nullptr_t __get_nullptr_t() {return nullptr_t(0);}
49 #define nullptr _VSTD::__get_nullptr_t()
51 _LIBCPP_END_NAMESPACE_STD
53 #else // _LIBCPP_HAS_NO_NULLPTR
57 typedef decltype(nullptr) nullptr_t;
60 #endif // _LIBCPP_HAS_NO_NULLPTR
62 #endif // _LIBCPP_NULLPTR