Performance test: std::endl vs "\n"

benchmark.cpp

#include <iostream>
#include <fstream>
#include <vector>
#include <chrono>

typedef void (*void_func_ptr_t)(void);
const int COUNT = 9999999;

struct Test
{
	std::string name;
	void_func_ptr_t function;
};

void withNewLine()
{
	std::ofstream file("output_endl.txt");
	
	for (int i = 0; i < COUNT; ++i)
		file << "Message " << i + 1 << "\n";
}

void withEndl()
{
	std::ofstream file("output_endl.txt");
	
	for (int i = 0; i < COUNT; ++i)
		file << "Message " << i + 1 << std::endl;
}

int main()
{
	std::vector<Test> tests;

	tests.push_back({
		"\\n",
		withNewLine
	});
	
	tests.push_back({
		"std::endl",
		withEndl
	});

	for (auto test : tests)
	{
		auto startTime = std::chrono::high_resolution_clock::now();
		test.function();
		auto endTime = std::chrono::high_resolution_clock::now();

		std::cout << "Test " << test.name << "\n";
		std::cout << std::chrono::duration_cast<std::chrono::milliseconds>(endTime - startTime).count() << " ms\n";
	}
}