creal(3) - Linux man page

Name

creal, crealf, creall - get real part of a complex number

#include <complex.h>

double creal(double complex z);
float crealf(float complex z);
long double creall(long double complex z);

Link with -lm.

The creal() function returns the real part of the complex number z.

One has:

z = creal(z) + I * cimag(z)

These functions first appeared in glibc in version 2.1.

C99.

The gcc supports also __real__. That is a GNU extension.

complex(5)