Function pipeline_cpp20_std_ranges

less_slow.cpp:3953–3973

}

static void pipeline_cpp20_std_ranges(bm::State &state) {
    std::uint64_t sum = 0, count = 0;
    for (auto _ : state) {
        auto pipeline =                                                                    //
            std::views::iota(pipe_start, pipe_end + 1) |                                   //
            std::views::filter(not_fn(is_power_of_two)) |                                  //
            std::views::filter(not_fn(is_power_of_three)) |                                //
            std::views::transform([](std::uint64_t x) { return prime_factors_view(x); }) | //
            std::views::join;

        // Interestingly, STL still struggles with non-homogeneous ranges,
        // if the `begin` and `end` iterators are of different types:
        //
        //      std::uint64_t sum = std::accumulate(
        //          pipeline.begin(), pipeline.end(), std::uint64_t{0});
        //
        sum = 0, count = 0;
        for (std::uint64_t factor : pipeline) sum += factor, count++;
        if (count != 84 || sum != 645) state.SkipWithError("Incorrect result");
    }
}

BENCHMARK(pipeline_cpp20_std_ranges);
#endif // defined(__cpp_lib_ranges)