"cannot open source file bits/stdc++.h" in Visual Studio

Question

#include <bits/stdc++.h>

If I put the above line at the top of my program.cpp file, it gives me the following error message:

cannot open source file "bits/stdc++.h"

How can I fix this?

Solution

It's an internal GCC header file. There is no guarantee that it will work anywhere else; even using it with GCC itself is poor practice for many reasons. Do not use it, ever.

How can I fix this?

Include those standard headers which you actually need. For example, if you need std::cout, then include <iostream>. If you need std::string, then include <string>. If you need std::ifstream, then include <fstream>.

As those are standard headers, they are guaranteed to work everywhere.

cppreference.com is a good free online source to find out which headers are needed for which component of the standard library. Let's take a non-obvious one, like std::ifstream. You just search for that name and you'll find http://en.cppreference.com/w/cpp/io/basic_ifstream. There, it says:

Defined in header <fstream>