tg_windows5.12.6/Telegram/ThirdParty/range-v3/example/comprehension_conversion.cpp

// Range v3 library
//
//  Copyright Eric Niebler 2019
//
//  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
//

///[comprehension_conversion]
// Use a range comprehension (views::for_each) to construct a custom range, and
// then convert it to a std::vector.

#include <iostream>
#include <vector>

#include <range/v3/range/conversion.hpp>
#include <range/v3/view/for_each.hpp>
#include <range/v3/view/iota.hpp>
#include <range/v3/view/repeat_n.hpp>
using std::cout;

int main()
{
    using namespace ranges;
    auto vi = views::for_each(views::ints(1, 6),
                              [](int i) { return yield_from(views::repeat_n(i, i)); }) |
              to<std::vector>();
    // prints: [1,2,2,3,3,3,4,4,4,4,5,5,5,5,5]
    cout << views::all(vi) << '\n';
}
///[comprehension_conversion]