xref: /freebsd/contrib/llvm-project/libcxx/include/__algorithm/clamp.h (revision 1fd880742ace94e11fa60ee0b074f0b18e54c54f)
1  //===----------------------------------------------------------------------===//
2  //
3  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4  // See https://llvm.org/LICENSE.txt for license information.
5  // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6  //
7  //===----------------------------------------------------------------------===//
8  
9  #ifndef _LIBCPP___ALGORITHM_CLAMP_H
10  #define _LIBCPP___ALGORITHM_CLAMP_H
11  
12  #include <__algorithm/comp.h>
13  #include <__assert>
14  #include <__config>
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  template <class _Tp, class _Compare>
24  _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI constexpr const _Tp&
25  clamp(_LIBCPP_LIFETIMEBOUND const _Tp& __v,
26        _LIBCPP_LIFETIMEBOUND const _Tp& __lo,
27        _LIBCPP_LIFETIMEBOUND const _Tp& __hi,
28        _Compare __comp) {
29    _LIBCPP_ASSERT_ARGUMENT_WITHIN_DOMAIN(!__comp(__hi, __lo), "Bad bounds passed to std::clamp");
30    return __comp(__v, __lo) ? __lo : __comp(__hi, __v) ? __hi : __v;
31  }
32  
33  template <class _Tp>
34  _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI constexpr const _Tp&
35  clamp(_LIBCPP_LIFETIMEBOUND const _Tp& __v,
36        _LIBCPP_LIFETIMEBOUND const _Tp& __lo,
37        _LIBCPP_LIFETIMEBOUND const _Tp& __hi) {
38    return std::clamp(__v, __lo, __hi, __less<>());
39  }
40  #endif
41  
42  _LIBCPP_END_NAMESPACE_STD
43  
44  #endif // _LIBCPP___ALGORITHM_CLAMP_H
45