libcxx/include/__algorithm/minmax.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_MINMAX_H
  10 #define _LIBCPP___ALGORITHM_MINMAX_H
  11
  12 #include <__algorithm/comp.h>
  13 #include <__algorithm/minmax_element.h>
  14 #include <__config>
  15 #include <__functional/identity.h>
  16 #include <__type_traits/is_callable.h>
  17 #include <__utility/pair.h>
  18 #include <initializer_list>
  19
  20 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  21 #  pragma GCC system_header
  22 #endif
  23
  24 _LIBCPP_BEGIN_NAMESPACE_STD
  25
  26 template<class _Tp, class _Compare>
  27 _LIBCPP_NODISCARD_EXT inline
  28 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX14
  29 pair<const _Tp&, const _Tp&>
  30 minmax(_LIBCPP_LIFETIMEBOUND const _Tp& __a, _LIBCPP_LIFETIMEBOUND const _Tp& __b, _Compare __comp)
  31 {
  32     return __comp(__b, __a) ? pair<const _Tp&, const _Tp&>(__b, __a) :
  33                               pair<const _Tp&, const _Tp&>(__a, __b);
  34 }
  35
  36 template<class _Tp>
  37 _LIBCPP_NODISCARD_EXT inline
  38 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX14
  39 pair<const _Tp&, const _Tp&>
  40 minmax(_LIBCPP_LIFETIMEBOUND const _Tp& __a, _LIBCPP_LIFETIMEBOUND const _Tp& __b)
  41 {
  42     return std::minmax(__a, __b, __less<>());
  43 }
  44
  45 #ifndef _LIBCPP_CXX03_LANG
  46
  47 template<class _Tp, class _Compare>
  48 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14
  49 pair<_Tp, _Tp> minmax(initializer_list<_Tp> __t, _Compare __comp) {
  50     static_assert(__is_callable<_Compare, _Tp, _Tp>::value, "The comparator has to be callable");
  51     __identity __proj;
  52     auto __ret = std::__minmax_element_impl(__t.begin(), __t.end(), __comp, __proj);
  53     return pair<_Tp, _Tp>(*__ret.first, *__ret.second);
  54 }
  55
  56 template<class _Tp>
  57 _LIBCPP_NODISCARD_EXT inline
  58 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX14
  59 pair<_Tp, _Tp>
  60 minmax(initializer_list<_Tp> __t)
  61 {
  62     return std::minmax(__t, __less<>());
  63 }
  64
  65 #endif // _LIBCPP_CXX03_LANG
  66
  67 _LIBCPP_END_NAMESPACE_STD
  68
  69 #endif // _LIBCPP___ALGORITHM_MINMAX_H