Richard Smith | 72d7577 | 2015-10-08 20:34:11 +0000 | [diff] [blame] | 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 | |
Eric Fiselier | c3589a8 | 2017-01-04 23:56:00 +0000 | [diff] [blame] | 24 | struct _LIBCPP_TEMPLATE_VIS nullptr_t |
Richard Smith | 72d7577 | 2015-10-08 20:34:11 +0000 | [diff] [blame] | 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;} |
Richard Smith | 72d7577 | 2015-10-08 20:34:11 +0000 | [diff] [blame] | 45 | }; |
| 46 | |
| 47 | inline _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 | |
| 55 | namespace std |
| 56 | { |
| 57 | typedef decltype(nullptr) nullptr_t; |
| 58 | } |
| 59 | |
| 60 | #endif // _LIBCPP_HAS_NO_NULLPTR |
| 61 | |
| 62 | #endif // _LIBCPP_NULLPTR |