Standard C++ classes

[ceh2624]

Hi gang,
I'm new to QT but not new to C++. I'm using QT Creator 3.2.2 on Ubuntu 14 with GCC 4.7.

I want to use functions I've already written and tested. I think my problem is that when I use:
@#include <string> //and
#include <vector>@

QT seems to not recognise them. It does know about them, however as evidenced by hovering over the #include.

So far I've learnt to compensate by using QString

I would really like to use things like <chrono>, <ctime>, <cstdlib> and <cmath>. What step am I missing it Qt Creator?

Cheers
Charles