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_RANGES_CLAMP_H 10 #define _LIBCPP___ALGORITHM_RANGES_CLAMP_H 11 12 #include <__assert> 13 #include <__config> 14 #include <__functional/identity.h> 15 #include <__functional/invoke.h> 16 #include <__functional/ranges_operations.h> 17 #include <__iterator/concepts.h> 18 #include <__iterator/projected.h> 19 #include <__utility/forward.h> 20 21 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 22 # pragma GCC system_header 23 #endif 24 25 _LIBCPP_PUSH_MACROS 26 #include <__undef_macros> 27 28 #if _LIBCPP_STD_VER >= 20 29 30 _LIBCPP_BEGIN_NAMESPACE_STD 31 32 namespace ranges { 33 struct __clamp { 34 template <class _Type, 35 class _Proj = identity, 36 indirect_strict_weak_order<projected<const _Type*, _Proj>> _Comp = ranges::less> 37 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr const _Type& operator()( 38 const _Type& __value, const _Type& __low, const _Type& __high, _Comp __comp = {}, _Proj __proj = {}) const { 39 _LIBCPP_ASSERT_ARGUMENT_WITHIN_DOMAIN( 40 !bool(std::invoke(__comp, std::invoke(__proj, __high), std::invoke(__proj, __low))), 41 "Bad bounds passed to std::ranges::clamp"); 42 43 auto&& __projected = std::invoke(__proj, __value); 44 if (std::invoke(__comp, std::forward<decltype(__projected)>(__projected), std::invoke(__proj, __low))) 45 return __low; 46 else if (std::invoke(__comp, std::invoke(__proj, __high), std::forward<decltype(__projected)>(__projected))) 47 return __high; 48 else 49 return __value; 50 } 51 }; 52 53 inline namespace __cpo { 54 inline constexpr auto clamp = __clamp{}; 55 } // namespace __cpo 56 } // namespace ranges 57 58 _LIBCPP_END_NAMESPACE_STD 59 60 #endif // _LIBCPP_STD_VER >= 20 61 62 _LIBCPP_POP_MACROS 63 64 #endif // _LIBCPP___ALGORITHM_RANGES_CLAMP_H 65