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 namespace __clamp { 34 struct __fn { 35 template <class _Type, 36 class _Proj = identity, 37 indirect_strict_weak_order<projected<const _Type*, _Proj>> _Comp = ranges::less> 38 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr const _Type& operator()( 39 const _Type& __value, const _Type& __low, const _Type& __high, _Comp __comp = {}, _Proj __proj = {}) const { 40 _LIBCPP_ASSERT_ARGUMENT_WITHIN_DOMAIN( 41 !bool(std::invoke(__comp, std::invoke(__proj, __high), std::invoke(__proj, __low))), 42 "Bad bounds passed to std::ranges::clamp"); 43 44 auto&& __projected = std::invoke(__proj, __value); 45 if (std::invoke(__comp, std::forward<decltype(__projected)>(__projected), std::invoke(__proj, __low))) 46 return __low; 47 else if (std::invoke(__comp, std::invoke(__proj, __high), std::forward<decltype(__projected)>(__projected))) 48 return __high; 49 else 50 return __value; 51 } 52 }; 53 } // namespace __clamp 54 55 inline namespace __cpo { 56 inline constexpr auto clamp = __clamp::__fn{}; 57 } // namespace __cpo 58 } // namespace ranges 59 60 _LIBCPP_END_NAMESPACE_STD 61 62 #endif // _LIBCPP_STD_VER >= 20 63 64 _LIBCPP_POP_MACROS 65 66 #endif // _LIBCPP___ALGORITHM_RANGES_CLAMP_H 67