libcxx/include/__algorithm/clamp.h

   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 [[nodiscard]] 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 [[nodiscard]] 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