// std::endlでflush()。時間測定と1行/秒機能付きバッファ懸念OS順序懸念あり。
// 混ざった行が出来たり上書き消滅してもいい人向け。
#include <iostream>
#include <fstream>
#include <chrono>
#include <thread>
using namespace std::chrono;
template<typename T, typename CallbackFunc, typename TargetFunc, typename... Args>
void measure(CallbackFunc callback, TargetFunc f, Args... args) {
auto start = high_resolution_clock::now();
auto result = f(args...);
auto end = high_resolution_clock::now();
callback(result, duration_cast<T>(end - start).count());
}
int write_to_file(const char* path, const char* sts) {
std::ofstream f(path, std::ios_base::app);
for (int i = 0; i < 10; ++i) {
f << sts << std::endl;
//std::this_thread::sleep_for(1s);
}
return 0;
}
int main(int argc, char* argv[]) {
int ret = -1;
measure<microseconds>(
[&](auto result, auto time) {ret = result; std::cout << time << std::endl; },
&write_to_file, "hoge.txt", (argc > 1 ? argv[1] : "hoge"));
return ret;
}