C++超高精度计时器

#include <chrono>
#include <QDebug>
#pragma execution_character_set("utf-8")
/*1 秒（s） = 1,000 毫秒（ms） = 1,000,000 微秒（μs） = 1,000,000,000 纳秒（ns）*/

class _Clock {
public:
	_Clock() : m_StartTimepoint(std::chrono::high_resolution_clock::now()) {}

	void setStop() {
		auto endTimepoint = std::chrono::high_resolution_clock::now();

		// 转纳秒，并计算自纪元(Epoch)以来的纳秒数
		auto startNs = std::chrono::time_point_cast<std::chrono::nanoseconds>(m_StartTimepoint).time_since_epoch().count();
		auto endNs = std::chrono::time_point_cast<std::chrono::nanoseconds>(endTimepoint).time_since_epoch().count();

		// 时间差，代码执行时间的纳秒数
		auto ns = endNs - startNs;

		// 微秒
		std::chrono::microseconds micro = std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::nanoseconds(ns));
		auto us = micro.count();

		// 毫秒
		std::chrono::milliseconds milli = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::nanoseconds(ns));
		auto ms = milli.count();

		// 秒
		std::chrono::seconds seconds = std::chrono::duration_cast<std::chrono::seconds>(std::chrono::nanoseconds(ns));
		auto s = seconds.count();

		qDebug() << "转换cast \t 耗时:" << ns << " ns \t" << us << " us \t" << ms << " ms \t" << s << " s";

		auto us2 = ns / 1000.;			// 微秒
		auto ms2 = ns / 1000000.;		// 毫秒
		auto s2 = ns / 1000000000.;		// 秒

		qDebug() << "比例: \t 耗时:" << ns << " ns \t" << us2 << " us \t" << ms2 << " ms \t" << s2 << " s";
	}

private:
	std::chrono::time_point<std::chrono::high_resolution_clock> m_StartTimepoint;
};

• 使用

_Clock _c;

/*耗时操作*/

_c.setStop();