xref: /freebsd/contrib/llvm-project/libcxx/include/__iterator/empty.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1fe6060f1SDimitry Andric // -*- C++ -*-
2fe6060f1SDimitry Andric //===----------------------------------------------------------------------===//
3fe6060f1SDimitry Andric //
4fe6060f1SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5fe6060f1SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
6fe6060f1SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7fe6060f1SDimitry Andric //
8fe6060f1SDimitry Andric //===----------------------------------------------------------------------===//
9fe6060f1SDimitry Andric 
10fe6060f1SDimitry Andric #ifndef _LIBCPP___ITERATOR_EMPTY_H
11fe6060f1SDimitry Andric #define _LIBCPP___ITERATOR_EMPTY_H
12fe6060f1SDimitry Andric 
13fe6060f1SDimitry Andric #include <__config>
14fe6060f1SDimitry Andric #include <cstddef>
15fe6060f1SDimitry Andric #include <initializer_list>
16fe6060f1SDimitry Andric 
17fe6060f1SDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
18fe6060f1SDimitry Andric #  pragma GCC system_header
19fe6060f1SDimitry Andric #endif
20fe6060f1SDimitry Andric 
21fe6060f1SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD
22fe6060f1SDimitry Andric 
2306c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 17
24fe6060f1SDimitry Andric 
25fe6060f1SDimitry Andric template <class _Cont>
26*0fca6ea1SDimitry Andric [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto
27*0fca6ea1SDimitry Andric empty(const _Cont& __c) noexcept(noexcept(__c.empty())) -> decltype(__c.empty()) {
28cb14a3feSDimitry Andric   return __c.empty();
29cb14a3feSDimitry Andric }
30fe6060f1SDimitry Andric 
31fe6060f1SDimitry Andric template <class _Tp, size_t _Sz>
empty(const _Tp (&)[_Sz])32*0fca6ea1SDimitry Andric [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool empty(const _Tp (&)[_Sz]) noexcept {
33cb14a3feSDimitry Andric   return false;
34cb14a3feSDimitry Andric }
35fe6060f1SDimitry Andric 
36fe6060f1SDimitry Andric template <class _Ep>
empty(initializer_list<_Ep> __il)37*0fca6ea1SDimitry Andric [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool empty(initializer_list<_Ep> __il) noexcept {
38cb14a3feSDimitry Andric   return __il.size() == 0;
39cb14a3feSDimitry Andric }
40fe6060f1SDimitry Andric 
4106c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 17
42fe6060f1SDimitry Andric 
43fe6060f1SDimitry Andric _LIBCPP_END_NAMESPACE_STD
44fe6060f1SDimitry Andric 
45fe6060f1SDimitry Andric #endif // _LIBCPP___ITERATOR_EMPTY_H
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