1 // -*- C++ -*- 2 //===----------------------------------------------------------------------===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef _LIBCPP___ITERATOR_EMPTY_H 11 #define _LIBCPP___ITERATOR_EMPTY_H 12 13 #include <__config> 14 #include <initializer_list> 15 16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 17 # pragma GCC system_header 18 #endif 19 20 _LIBCPP_BEGIN_NAMESPACE_STD 21 22 #if _LIBCPP_STD_VER >= 17 23 24 template <class _Cont> 25 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto 26 empty(const _Cont& __c) noexcept(noexcept(__c.empty())) -> decltype(__c.empty()) { 27 return __c.empty(); 28 } 29 30 template <class _Tp, size_t _Sz> 31 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool empty(const _Tp (&)[_Sz]) noexcept { 32 return false; 33 } 34 35 template <class _Ep> 36 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool empty(initializer_list<_Ep> __il) noexcept { 37 return __il.size() == 0; 38 } 39 40 #endif // _LIBCPP_STD_VER >= 17 41 42 _LIBCPP_END_NAMESPACE_STD 43 44 #endif // _LIBCPP___ITERATOR_EMPTY_H 45