v3/algorithm/max_element.hpp

0001 /// \file
0002 // Range v3 library
0003 //
0004 //  Copyright Eric Niebler 2014-present
0005 //
0006 //  Use, modification and distribution is subject to the
0007 //  Boost Software License, Version 1.0. (See accompanying
0008 //  file LICENSE_1_0.txt or copy at
0009 //  http://www.boost.org/LICENSE_1_0.txt)
0010 //
0011 // Project home: https://github.com/ericniebler/range-v3
0012 //
0013 #ifndef RANGES_V3_ALGORITHM_MAX_ELEMENT_HPP
0014 #define RANGES_V3_ALGORITHM_MAX_ELEMENT_HPP
0015
0016 #include <range/v3/range_fwd.hpp>
0017
0018 #include <range/v3/functional/comparisons.hpp>
0019 #include <range/v3/functional/identity.hpp>
0020 #include <range/v3/functional/invoke.hpp>
0021 #include <range/v3/iterator/concepts.hpp>
0022 #include <range/v3/iterator/operations.hpp>
0023 #include <range/v3/iterator/traits.hpp>
0024 #include <range/v3/range/access.hpp>
0025 #include <range/v3/range/concepts.hpp>
0026 #include <range/v3/range/dangling.hpp>
0027 #include <range/v3/range/traits.hpp>
0028 #include <range/v3/utility/static_const.hpp>
0029
0030 #include <range/v3/detail/prologue.hpp>
0031
0032 namespace ranges
0033 {
0034     /// \addtogroup group-algorithms
0035     /// @{
0036     RANGES_FUNC_BEGIN(max_element)
0037
0038         /// \brief function template \c max_element
0039         template(typename I, typename S, typename C = less, typename P = identity)(
0040             requires forward_iterator<I> AND sentinel_for<S, I> AND
0041             indirect_strict_weak_order<C, projected<I, P>>)
0042         constexpr I RANGES_FUNC(max_element)(I first, S last, C pred = C{}, P proj = P{})
0043         {
0044             if(first != last)
0045                 for(auto tmp = next(first); tmp != last; ++tmp)
0046                     if(invoke(pred, invoke(proj, *first), invoke(proj, *tmp)))
0047                         first = tmp;
0048             return first;
0049         }
0050
0051         /// \overload
0052         template(typename Rng, typename C = less, typename P = identity)(
0053             requires forward_range<Rng> AND
0054             indirect_strict_weak_order<C, projected<iterator_t<Rng>, P>>)
0055         constexpr borrowed_iterator_t<Rng> //
0056         RANGES_FUNC(max_element)(Rng && rng, C pred = C{}, P proj = P{})
0057         {
0058             return (*this)(begin(rng), end(rng), std::move(pred), std::move(proj));
0059         }
0060
0061     RANGES_FUNC_END(max_element)
0062
0063     namespace cpp20
0064     {
0065         using ranges::max_element;
0066     }
0067     /// @}
0068 } // namespace ranges
0069
0070 #include <range/v3/detail/epilogue.hpp>
0071
0072 #endif