xref: /openbsd-src/gnu/llvm/libcxx/include/__algorithm/ranges_clamp.h (revision 4bdff4bed0e3d54e55670334c7d0077db4170f86)
1*4bdff4beSrobert //===----------------------------------------------------------------------===//
2*4bdff4beSrobert //
3*4bdff4beSrobert // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*4bdff4beSrobert // See https://llvm.org/LICENSE.txt for license information.
5*4bdff4beSrobert // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*4bdff4beSrobert //
7*4bdff4beSrobert //===----------------------------------------------------------------------===//
8*4bdff4beSrobert 
9*4bdff4beSrobert #ifndef _LIBCPP___ALGORITHM_RANGES_CLAMP_H
10*4bdff4beSrobert #define _LIBCPP___ALGORITHM_RANGES_CLAMP_H
11*4bdff4beSrobert 
12*4bdff4beSrobert #include <__assert>
13*4bdff4beSrobert #include <__config>
14*4bdff4beSrobert #include <__functional/identity.h>
15*4bdff4beSrobert #include <__functional/invoke.h>
16*4bdff4beSrobert #include <__functional/ranges_operations.h>
17*4bdff4beSrobert #include <__iterator/concepts.h>
18*4bdff4beSrobert #include <__iterator/projected.h>
19*4bdff4beSrobert #include <__utility/forward.h>
20*4bdff4beSrobert 
21*4bdff4beSrobert #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
22*4bdff4beSrobert #  pragma GCC system_header
23*4bdff4beSrobert #endif
24*4bdff4beSrobert 
25*4bdff4beSrobert #if _LIBCPP_STD_VER > 17
26*4bdff4beSrobert 
27*4bdff4beSrobert _LIBCPP_BEGIN_NAMESPACE_STD
28*4bdff4beSrobert 
29*4bdff4beSrobert namespace ranges {
30*4bdff4beSrobert namespace __clamp {
31*4bdff4beSrobert struct __fn {
32*4bdff4beSrobert 
33*4bdff4beSrobert   template <class _Type,
34*4bdff4beSrobert             class _Proj = identity,
35*4bdff4beSrobert             indirect_strict_weak_order<projected<const _Type*, _Proj>> _Comp = ranges::less>
36*4bdff4beSrobert   _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr
operator__fn37*4bdff4beSrobert   const _Type& operator()(const _Type& __value,
38*4bdff4beSrobert                           const _Type& __low,
39*4bdff4beSrobert                           const _Type& __high,
40*4bdff4beSrobert                           _Comp __comp = {},
41*4bdff4beSrobert                           _Proj __proj = {}) const {
42*4bdff4beSrobert     _LIBCPP_ASSERT(!bool(std::invoke(__comp, std::invoke(__proj, __high), std::invoke(__proj, __low))),
43*4bdff4beSrobert                    "Bad bounds passed to std::ranges::clamp");
44*4bdff4beSrobert 
45*4bdff4beSrobert     if (std::invoke(__comp, std::invoke(__proj, __value), std::invoke(__proj, __low)))
46*4bdff4beSrobert       return __low;
47*4bdff4beSrobert     else if (std::invoke(__comp, std::invoke(__proj, __high), std::invoke(__proj, __value)))
48*4bdff4beSrobert       return __high;
49*4bdff4beSrobert     else
50*4bdff4beSrobert       return __value;
51*4bdff4beSrobert   }
52*4bdff4beSrobert 
53*4bdff4beSrobert };
54*4bdff4beSrobert } // namespace __clamp
55*4bdff4beSrobert 
56*4bdff4beSrobert inline namespace __cpo {
57*4bdff4beSrobert   inline constexpr auto clamp = __clamp::__fn{};
58*4bdff4beSrobert } // namespace __cpo
59*4bdff4beSrobert } // namespace ranges
60*4bdff4beSrobert 
61*4bdff4beSrobert _LIBCPP_END_NAMESPACE_STD
62*4bdff4beSrobert 
63*4bdff4beSrobert #endif // _LIBCPP_STD_VER > 17
64*4bdff4beSrobert 
65*4bdff4beSrobert #endif // _LIBCPP___ALGORITHM_RANGES_CLAMP_H
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