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 <__type_traits/common_type.h>
15#include <__type_traits/make_signed.h>
16#include <cstddef>
17
18#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
19#  pragma GCC system_header
20#endif
21
22_LIBCPP_BEGIN_NAMESPACE_STD
23
24#if _LIBCPP_STD_VER > 14
25
26template <class _Cont>
27_LIBCPP_INLINE_VISIBILITY
28constexpr auto size(const _Cont& __c)
29_NOEXCEPT_(noexcept(__c.size()))
30-> decltype        (__c.size())
31{ return            __c.size(); }
32
33template <class _Tp, size_t _Sz>
34_LIBCPP_INLINE_VISIBILITY
35constexpr size_t size(const _Tp (&)[_Sz]) noexcept { return _Sz; }
36
37#if _LIBCPP_STD_VER > 17
38template <class _Cont>
39_LIBCPP_INLINE_VISIBILITY
40constexpr auto ssize(const _Cont& __c)
41_NOEXCEPT_(noexcept(static_cast<common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>>(__c.size())))
42->                              common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>
43{ return            static_cast<common_type_t<ptrdiff_t, make_signed_t<decltype(__c.size())>>>(__c.size()); }
44
45// GCC complains about the implicit conversion from ptrdiff_t to size_t in
46// the array bound.
47_LIBCPP_DIAGNOSTIC_PUSH
48_LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wsign-conversion")
49template <class _Tp, ptrdiff_t _Sz>
50_LIBCPP_INLINE_VISIBILITY
51constexpr ptrdiff_t ssize(const _Tp (&)[_Sz]) noexcept { return _Sz; }
52_LIBCPP_DIAGNOSTIC_POP
53#endif
54
55#endif // _LIBCPP_STD_VER > 14
56
57_LIBCPP_END_NAMESPACE_STD
58
59#endif // _LIBCPP___ITERATOR_SIZE_H
60