1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef _LIBCPP___UTILITY_SWAP_H 10 #define _LIBCPP___UTILITY_SWAP_H 11 12 #include <__config> 13 #include <__utility/declval.h> 14 #include <__utility/move.h> 15 #include <type_traits> 16 #include <cstddef> 17 18 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 19 #pragma GCC system_header 20 #endif 21 22 _LIBCPP_PUSH_MACROS 23 #include <__undef_macros> 24 25 _LIBCPP_BEGIN_NAMESPACE_STD 26 27 #ifndef _LIBCPP_CXX03_LANG 28 template <class _Tp> 29 using __swap_result_t = typename enable_if<is_move_constructible<_Tp>::value && is_move_assignable<_Tp>::value>::type; 30 #else 31 template <class> 32 using __swap_result_t = void; 33 #endif 34 35 template <class _Tp> 36 inline _LIBCPP_INLINE_VISIBILITY __swap_result_t<_Tp> _LIBCPP_CONSTEXPR_AFTER_CXX17 swap(_Tp& __x, _Tp& __y) 37 _NOEXCEPT_(is_nothrow_move_constructible<_Tp>::value&& is_nothrow_move_assignable<_Tp>::value) { 38 _Tp __t(_VSTD::move(__x)); 39 __x = _VSTD::move(__y); 40 __y = _VSTD::move(__t); 41 } 42 43 template <class _Tp, size_t _Np> 44 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 typename enable_if<__is_swappable<_Tp>::value>::type 45 swap(_Tp (&__a)[_Np], _Tp (&__b)[_Np]) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value) { 46 for (size_t __i = 0; __i != _Np; ++__i) { 47 swap(__a[__i], __b[__i]); 48 } 49 } 50 51 _LIBCPP_END_NAMESPACE_STD 52 53 _LIBCPP_POP_MACROS 54 55 #endif // _LIBCPP___UTILITY_SWAP_H 56