axmol/thirdparty/range-v3/include/range/v3/algorithm/count.hpp

73 lines
2.1 KiB
C++

/// \file
// Range v3 library
//
// Copyright Eric Niebler 2014-present
//
// Use, modification and distribution is subject to the
// Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// Project home: https://github.com/ericniebler/range-v3
//
#ifndef RANGES_V3_ALGORITHM_COUNT_HPP
#define RANGES_V3_ALGORITHM_COUNT_HPP
#include <utility>
#include <range/v3/range_fwd.hpp>
#include <range/v3/functional/identity.hpp>
#include <range/v3/functional/invoke.hpp>
#include <range/v3/iterator/concepts.hpp>
#include <range/v3/iterator/traits.hpp>
#include <range/v3/range/access.hpp>
#include <range/v3/range/concepts.hpp>
#include <range/v3/range/traits.hpp>
#include <range/v3/utility/static_const.hpp>
#include <range/v3/detail/prologue.hpp>
namespace ranges
{
/// \addtogroup group-algorithms
/// @{
RANGES_FUNC_BEGIN(count)
/// \brief function template \c count
template(typename I, typename S, typename V, typename P = identity)(
requires input_iterator<I> AND sentinel_for<S, I> AND
indirect_relation<equal_to, projected<I, P>, V const *>)
constexpr iter_difference_t<I> //
RANGES_FUNC(count)(I first, S last, V const & val, P proj = P{})
{
iter_difference_t<I> n = 0;
for(; first != last; ++first)
if(invoke(proj, *first) == val)
++n;
return n;
}
/// \overload
template(typename Rng, typename V, typename P = identity)(
requires input_range<Rng> AND
indirect_relation<equal_to, projected<iterator_t<Rng>, P>, V const *>)
constexpr iter_difference_t<iterator_t<Rng>> //
RANGES_FUNC(count)(Rng && rng, V const & val, P proj = P{})
{
return (*this)(begin(rng), end(rng), val, std::move(proj));
}
RANGES_FUNC_END(count)
namespace cpp20
{
using ranges::count;
}
/// @}
} // namespace ranges
#include <range/v3/detail/epilogue.hpp>
#endif