26 <tgmath.h> Type-Generic Math Functions

These are type-generic macros that are wrappers around the math functions in <math.h> and <complex.h>. This header includes both of those.

But on the surface, you can think of them as being able to use, say, the sqrt() function with any type without needed to think about if it’s double or long double or even complex.

These are the defined macros—some of them don’t have a counterpart in the real or complex space. Type suffixes are omitted in the table on the Real and Complex columns. None of the generic macros have type suffixes.

26.1 Example

Here’s an example where we call the type-generic sqrt() function on a variety of types.

#include <stdio.h>
#include <tgmath.h>

int main(void)
{
    double x = 12.8;
    long double y = 34.9;
    double complex z = 1 + 2 * I;

    double x_result;
    long double y_result;
    double complex z_result;

    // We call the same sqrt() function--it's type-generic!
    x_result = sqrt(x);
    y_result = sqrt(y);
    z_result = sqrt(z);

    printf("x_result: %f\n", x_result);
    printf("y_result: %Lf\n", y_result);
    printf("z_result: %f + %fi\n", creal(z_result), cimag(z_result));
}

Output:

x_result: 3.577709
y_result: 5.907622
z_result: 1.272020 + 0.786151i