CREAL(3) Library Functions Manual CREAL(3)

creal, crealf, creall
complex real functions

#include <complex.h>

double
creal(double complex z);

float
crealf(float complex z);

long double
creall(long double complex z);

#include <tgmath.h>

complex-float
creal(complex-float z);

These functions compute the real part of z.

These functions return the real part value.

No errors are defined.

For a variable z of type complex:
z == creal(z) + cimag(z)*I

carg(3), cimag(3), conj(3), cproj(3), IEEE Std 1003.1-2001 (“POSIX.1”)complex.h

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .
September 27, 2017 NetBSD 9.0