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 <cstddef> 15 #include <initializer_list> 16 17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 18 # pragma GCC system_header 19 #endif 20 21 _LIBCPP_BEGIN_NAMESPACE_STD 22 23 #if _LIBCPP_STD_VER >= 17 24 25 template <class _Cont> 26 _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI constexpr auto empty(const _Cont& __c) 27 _NOEXCEPT_(noexcept(__c.empty())) -> decltype(__c.empty()) { 28 return __c.empty(); 29 } 30 31 template <class _Tp, size_t _Sz> 32 _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI constexpr bool empty(const _Tp (&)[_Sz]) noexcept { 33 return false; 34 } 35 36 template <class _Ep> 37 _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI constexpr bool empty(initializer_list<_Ep> __il) noexcept { 38 return __il.size() == 0; 39 } 40 41 #endif // _LIBCPP_STD_VER >= 17 42 43 _LIBCPP_END_NAMESPACE_STD 44 45 #endif // _LIBCPP___ITERATOR_EMPTY_H 46