#include libraries in header files?

[kevin06s]

I am somewhat confused about how to tell a header file to #include <iostream>.
I am writing a header with functions that I will want to reuse many times, and I need the iostream library for it, but I do not know if it is always included in the file that is using the header. Should I use #include, #ifndef, or just always make sure to put it in the file including the header?

[firedraco]

Inside the .h just put #include <iostream> . It's as simple as that.

[Zhuge]

If you are splitting these utility functions into a cpp and a header, you might also be able to include only in the source so long as you don't use any <iostream> types in the header. I don't remember if this would speed up compile up at all, but with standard headers I don't think it would matter too much.