islessequal

Defined in header <math.h> 
#define islessequal(x, y) /* implementation defined */
 (since C99)

Determines if the floating point number x is less than or equal to the floating-point number y, without setting floating-point exceptions.

Parameters

x - floating point value
y - floating point value

Return value

Nonzero integral value if x <= y, ​0​ otherwise.

Notes

The built-in operator<= for floating-point numbers may raise FE_INVALID if one or both of the arguments is NaN. This function is a "quiet" version of operator<=.

Example

#include <stdio.h>
#include <math.h>
 
int main(void)
{
    printf("islessequal(2.0,1.0)      = %d\n", islessequal(2.0,1.0));
    printf("islessequal(1.0,2.0)      = %d\n", islessequal(1.0,2.0));
    printf("islessequal(1.0,1.0)      = %d\n", islessequal(1.0,1.0));
    printf("islessequal(INFINITY,1.0) = %d\n", islessequal(INFINITY,1.0));
    printf("islessequal(1.0,NAN)      = %d\n", islessequal(1.0,NAN));
 
    return 0;
}

Possible output:

islessequal(2.0,1.0)      = 0
islessequal(1.0,2.0)      = 1
islessequal(1.0,1.0)      = 1
islessequal(INFINITY,1.0) = 0
islessequal(1.0,NAN)      = 0

References

See also

isgreaterequal
(C99)
 checks if the first floating-point argument is greater or equal than the second
(function macro)
C++ documentation for islessequal

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