swap.h 1.6 KB

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  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. #ifndef _LIBCPP___UTILITY_SWAP_H
  9. #define _LIBCPP___UTILITY_SWAP_H
  10. #include <__config>
  11. #include <__utility/declval.h>
  12. #include <__utility/move.h>
  13. #include <cstddef>
  14. #include <type_traits>
  15. #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  16. # pragma GCC system_header
  17. #endif
  18. _LIBCPP_BEGIN_NAMESPACE_STD
  19. #ifndef _LIBCPP_CXX03_LANG
  20. template <class _Tp>
  21. using __swap_result_t = typename enable_if<is_move_constructible<_Tp>::value && is_move_assignable<_Tp>::value>::type;
  22. #else
  23. template <class>
  24. using __swap_result_t = void;
  25. #endif
  26. template <class _Tp>
  27. inline _LIBCPP_INLINE_VISIBILITY __swap_result_t<_Tp> _LIBCPP_CONSTEXPR_AFTER_CXX17 swap(_Tp& __x, _Tp& __y)
  28. _NOEXCEPT_(is_nothrow_move_constructible<_Tp>::value&& is_nothrow_move_assignable<_Tp>::value) {
  29. _Tp __t(_VSTD::move(__x));
  30. __x = _VSTD::move(__y);
  31. __y = _VSTD::move(__t);
  32. }
  33. template <class _Tp, size_t _Np>
  34. inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 typename enable_if<__is_swappable<_Tp>::value>::type
  35. swap(_Tp (&__a)[_Np], _Tp (&__b)[_Np]) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value) {
  36. for (size_t __i = 0; __i != _Np; ++__i) {
  37. swap(__a[__i], __b[__i]);
  38. }
  39. }
  40. _LIBCPP_END_NAMESPACE_STD
  41. #endif // _LIBCPP___UTILITY_SWAP_H