where is "namespace std" defined

[Lilium426]

Hello everyone.

I am wondering what is exactly in "namespace std", so I want to find out where it is.

Thanks for your help.

[Bazzy]

In the std namespace are all the standard symbols ( std means standard )
Everything declared in the C++ standard headers ( eg <iostream> <string> etc ) is in the std namespace

[guestgulkan]

The whole std namespace is NOT defined in one particular file/header.
Namespaces are open - this means you can add to them.
Each header file in the standard c++ library add it's particular stuff to the std namespace.
So #include <vector> will add the vector related bits.

[Lilium426]

Oh, I understand. Thanks!