Complex number

[SeyMohsenFls]

Hi guys.
I have programing a Qt app and want to use complex number.
I insert the #include <complex> in top of my code. But the Qt says:

error: use of undeclared identifier 'complex'

when i make a variable like this:

complex<double> Q;

pls help me. I'm beginner in Qt :-(

[JoeCFD]

@SeyMohsenFls said in Complex number:

#include <complex>

std::complex<double> Q;