Спринт 6. Упрощаем логирование.

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main.cpp
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#include <chrono>
#include <cstdlib>
#include <iostream>
#include <vector>
#include "log_duration.h"

using namespace std;

vector<int> ReverseVector(const vector<int>& source_vector) {
    vector<int> res;
    for (int i : source_vector) {
        res.insert(res.begin(), i);
    }
    return res;
}

int CountPops(const vector<int>& source_vector, int begin, int end) {
    int res = 0;
    for (int i = begin; i < end; ++i) {
        if (source_vector[i]) {
            ++res;
        }
    }
    return res;
}

void AppendRandom(vector<int>& v, int n) {
    for (int i = 0; i < n; ++i) {
        v.push_back(rand() % 2);
    }
}

void Operate() {
    {
        LogDuration logduration("Total"s);
        vector<int> random_bits;
        static const int N = 1 << 17;
        {
            LogDuration logduration("Append random"s);
            AppendRandom(random_bits, N);
        }

        vector<int> reversed_bits;
        {
            LogDuration logduration("Reverse"s);
            reversed_bits = ReverseVector(random_bits);
        }

        {
            LogDuration logduration("Counting"s);
            for (int i = 1, step = 1; i <= N; i += step, step *= 2) {
                double rate = CountPops(reversed_bits, 0, i) * 100. / i;
                cout << "After "s << i << " bits we found "s << rate << "% pops"s << endl;
            }
        }
    }
}

int main() {
    Operate();
}
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log_duration.h
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#pragma once

#include <chrono>
#include <iostream>

class LogDuration {
public:
    using Clock = std::chrono::steady_clock;
    std::string operation_name;

    LogDuration(std::string operation_name_) : operation_name(operation_name_){}

    ~LogDuration() {
        using namespace std::chrono;
        using namespace std::literals;

        const auto end_time = Clock::now();
        const auto dur = end_time - start_time_;
        std::cerr << operation_name << ": "s << duration_cast<milliseconds>(dur).count() << " ms"s << std::endl;
    }
private:
    const Clock::time_point start_time_ = Clock::now();
};