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_SIZE_H
11 #define _LIBCPP___ITERATOR_SIZE_H
12 
13 #include <__config>
14 #include <cstddef>
15 #include <type_traits>
16 
17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
18 #pragma GCC system_header
19 #endif
20 
21 _LIBCPP_PUSH_MACROS
22 #include <__undef_macros>
23 
24 _LIBCPP_BEGIN_NAMESPACE_STD
25 
26 #if _LIBCPP_STD_VER > 14
27 
28 template <class _Cont>
29 _LIBCPP_INLINE_VISIBILITY
30 constexpr auto size(const _Cont& __c)
31 _NOEXCEPT_(noexcept(__c.size()))
32 -> decltype        (__c.size())
33 { return            __c.size(); }
34 
35 template <class _Tp, size_t _Sz>
36 _LIBCPP_INLINE_VISIBILITY
37 constexpr size_t size(const _Tp (&)[_Sz]) noexcept { return _Sz; }
38 
39 #if _LIBCPP_STD_VER > 17
40 template <class _Cont>
41 _LIBCPP_INLINE_VISIBILITY
42 constexpr auto ssize(const _Cont& __c)
43 _NOEXCEPT_(noexcept(static_cast<common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>>(__c.size())))
44 ->                              common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>
45 { return            static_cast<common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>>(__c.size()); }
46 
47 template <class _Tp, ptrdiff_t _Sz>
48 _LIBCPP_INLINE_VISIBILITY
49 constexpr ptrdiff_t ssize(const _Tp (&)[_Sz]) noexcept { return _Sz; }
50 #endif
51 
52 #endif // _LIBCPP_STD_VER > 14
53 
54 _LIBCPP_END_NAMESPACE_STD
55 
56 _LIBCPP_POP_MACROS
57 
58 #endif // _LIBCPP___ITERATOR_SIZE_H
59