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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_GENERATE_N_HPP
#define RANGES_V3_ALGORITHM_GENERATE_N_HPP
#include <tuple>
#include <utility>
#include <range/v3/range_fwd.hpp>
#include <range/v3/algorithm/result_types.hpp>
#include <range/v3/functional/invoke.hpp>
#include <range/v3/iterator/concepts.hpp>
#include <range/v3/iterator/operations.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
/// @{
template<typename O, typename F>
using generate_n_result = detail::out_fun_result<O, F>;
RANGES_FUNC_BEGIN(generate_n)
/// \brief function template \c generate_n
template(typename O, typename F)(
requires invocable<F &> AND output_iterator<O, invoke_result_t<F &>>)
constexpr generate_n_result<O, F> //
RANGES_FUNC(generate_n)(O first, iter_difference_t<O> n, F fun)
{
RANGES_EXPECT(n >= 0);
auto norig = n;
auto b = uncounted(first);
for(; 0 != n; ++b, --n)
*b = invoke(fun);
return {recounted(first, b, norig), detail::move(fun)};
}
RANGES_FUNC_END(generate_n)
namespace cpp20
{
using ranges::generate_n;
using ranges::generate_n_result;
} // namespace cpp20
// @}
} // namespace ranges
#include <range/v3/detail/epilogue.hpp>
#endif
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