imaginary

#define imaginary _Imaginary

This macro expands to the keyword _Imaginary.

This is a convenience macro that makes it possible to use float imaginary, double imaginary, and long double imaginary as an alternative way to write the three pure imaginary C types float _Imaginary, double _Imaginary, and long double _Imaginary

As with any pure imaginary number support in C, this macro is only defined if the imaginary numbers are supported.

Notes

Programs are allowed to undefine and perhaps redefine the imaginary macro.

Example

#include <stdio.h>
#include <complex.h>
 
int main(void)
{
    double imaginary i = -2.0*I; // pure imaginary
    double f = 1.0; // pure real
    double complex z = f + i; // complex number
    printf("z = %.1f%+.1fi\n", creal(z), cimag(z));
}

z = 1.0-2.0i

References

• C17 standard (ISO/IEC 9899:2018):
• 7.3.1/5 imaginary (p: 136)
• G.6/1 imaginary (p: 391-392)
• C11 standard (ISO/IEC 9899:2011):
• 7.3.1/5 imaginary (p: 188)
• G.6/1 imaginary (p: 537)
• C99 standard (ISO/IEC 9899:1999):
• 7.3.1/3 imaginary (p: 170)
• G.6/1 imaginary (p: 472)

See also