Visual C ++的第二次编译速度比第一次更快？

Question

Why does this code compile within two very different time ranges in Visual Studio 2015:

#include "stdafx.h"
#include <Windows.h>
#include <iostream>


int main()
{
}

The first compilation is done in 1.49 seconds, and the second compilation is done in 0.15 seconds - why? I have not touched any precompilation settings, so I wonder why this is happening.

Answer 1

From the official man page :

Choose Build or Build Solution to compile only those project files and components that have changed since the most recent build.

So on the second build it does nothing, because there were no changes.

Choose Rebuild Solution to "clean" the solution and then build all project files and components.

So if you rebuild the solution the build times should be consistent.