How does #include <bits/stdc++.h> work in C++?

c++ gcc c++11 g++
GorvGoyl picture GorvGoyl · Aug 14, 2014 · Viewed 174.9k times · Source

I have read from a codeforces blog that if we add #include <bits/stdc++.h> in a C++ program then there is no need to include any other header files. How does #include <bits/stdc++.h> work and is it ok to use it instead of including individual header files?

Answer

Zelix picture Zelix · Aug 14, 2014

It is basically a header file that also includes every standard library and STL include file. The only purpose I can see for it would be for testing and education.

Se e.g. GCC 4.8.0 /bits/stdc++.h source.

Using it would include a lot of unnecessary stuff and increases compilation time.

Edit: As Neil says, it's an implementation for precompiled headers. If you set it up for precompilation correctly it could, in fact, speed up compilation time depending on your project. (https://gcc.gnu.org/onlinedocs/gcc/Precompiled-Headers.html)

I would, however, suggest that you take time to learn about each of the sl/stl headers and include them separately instead, and not use "super headers" except for precompilation purposes.

Related questions

error: use of deleted function

I've been working on some C++ code that a friend has written and I get the following error that I have never seen before when compiling with gcc4.6: error: use of deleted function ‘GameFSM_<std::array<C, 2ul&…

Read More
😃 (and other unicode characters) in identifiers not allowed by g++

I am 😞 to find that I cannot use 😃 as a valid identifier with g++ 4.7, even with the -fextended-identifiers option enabled: int main(int argc, const char* argv[]) { const char* 😃 = "I'm very happy"; return 0; } main.cpp:3:3: error: stray ‘\360’ in program main.…

Read More
undefined reference to 'std::cout'

Shall this be the example: #include <iostream> using namespace std; int main() { cout << "Hola, moondo.\n"; } It throws the error: gcc -c main.cpp gcc -o edit main.o main.o: In function `main': main.cpp:(.…

Read More