c++11 practice

benchmark.hpp

#ifndef __BENCHMARK_HPP_BY_GZSHI__
#define __BENCHMARK_HPP_BY_GZSHI__

#include <functional>
#include <chrono>

template<typename TClock, typename TFn, typename ...TArgs>
TClock benchmark(TFn&& fn, TArgs&&... args) {
	auto exec = std::bind(std::forward<TFn>(fn), std::forward<TArgs>(args)...);
	
	auto begin = std::chrono::steady_clock::now();
	exec();
	auto end = std::chrono::steady_clock::now();
	
	return std::chrono::duration_cast<TClock>(end - begin);
}


#endif


/* example
```cpp
#include "benchmark.hpp"
#include <iostream>

using namespace std;

int main(int argc, char** argv) {
	function<int64_t(int32_t)> fibonacci = [&](int32_t index) -> int64_t {
		return index < 2 ? index : (fibonacci(index - 1) + fibonacci(index - 2));
	}
	
	auto ms = benchmark<chrono::milliseconds>([&]() {
		for (auto i = 0; i < 35; ++i) {
			cout << "fibonacci(" << i << ") = " << fibonacci(i) << endl;
		}
	});
	cout << "total: " << ms << "ms" << endl;
	
	auto ns = benchmark<chrono::nanoseconds>([]() {
		int64_t sum = 0;
		for (auto i = 0; i < 1000000; ++i) {
			sum += i;
		}
		cout << "sum = " << sum << endl;
	});
	cout << "total: " << ns << "ns" << endl;
	
	return 0;
}

```
*/