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/// \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_IF_HPP
#define RANGES_V3_ALGORITHM_COUNT_IF_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_if)
/// \brief function template \c count_if
template(typename I, typename S, typename R, typename P = identity)(
requires input_iterator<I> AND sentinel_for<S, I> AND
indirect_unary_predicate<R, projected<I, P>>)
constexpr iter_difference_t<I> RANGES_FUNC(count_if)(I first, S last, R pred, P proj = P{})
{
iter_difference_t<I> n = 0;
for(; first != last; ++first)
if(invoke(pred, invoke(proj, *first)))
++n;
return n;
}
/// \overload
template(typename Rng, typename R, typename P = identity)(
requires input_range<Rng> AND
indirect_unary_predicate<R, projected<iterator_t<Rng>, P>>)
constexpr iter_difference_t<iterator_t<Rng>> //
RANGES_FUNC(count_if)(Rng && rng, R pred, P proj = P{})
{
return (*this)(begin(rng), end(rng), std::move(pred), std::move(proj));
}
RANGES_FUNC_END(count_if)
namespace cpp20
{
using ranges::count_if;
}
/// @}
} // namespace ranges
#include <range/v3/detail/epilogue.hpp>
#endif
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