islessgreater

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

Determines if the floating-point number x is less than or greater than 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 || x > y, 0 otherwise.

Notes

The built-in operator< and 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 the expression x < y || x > y. The macro does not evaluate x and y twice.

Example

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

Possible output:

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

References

C23 standard (ISO/IEC 9899:2024):

7.12.14.5 The islessgreater macro (p: TBD)
F.10.11 Comparison macros (p: TBD)

C17 standard (ISO/IEC 9899:2018):

7.12.14.5 The islessgreater macro (p: TBD)
F.10.11 Comparison macros (p: TBD)

C11 standard (ISO/IEC 9899:2011):

7.12.14.5 The islessgreater macro (p: 261)
F.10.11 Comparison macros (p: 531)

C99 standard (ISO/IEC 9899:1999):

7.12.14.5 The islessgreater macro (p: 241-242)