Test of tgmath.h

tgmath_test.c

// This file demonstrates that if `tgmath.h` is included, it doesn't matter if
// `math.h` is also included and which order the include statements appear.

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

int main() {
    printf("%.20f\n", sinf((float) 5.0));
    printf("%.20f\n", sin((double) 5.0));
    printf("%.20f\n", sin((float) 5.0));
}

// The first two lines print the same result regardless of the includes. The
// last line behaves like `sinf` if and only if `tgmath.h` is included.