the sequence of including headfiles

[a7300235]

the sequence of including headfiles may affect the success of compilation.
and now i am wondering if it is important to include headfiles in a particular sequence if all the headfiles included in my program are the headfiles all included in GNU C/C++ Library.
just like:

#include<iostream>
#include<vector> 

#include<vector>
#include<iostream> 

(just an example.both complier)

[helios]

the sequence of including headfiles may affect the success of compilation.

That's only the case if your headers are poorly-written. If only one order of inclusion is valid then probably one of those headers needs to include the other.

Standard headers do not care in which order they're included.

[Ganado]

No, the ordering of standard library headers should not matter (assuming you don't have code in-between the #includes, then it would of course matter).

This might not be true in general for custom headers, where you could have, for example, a conflicting macro that bleeds into the other header.