C++

Reference

<cmath> (math.h)

macro
<cmath> <ctgmath>

isless

macro
isless(x,y)
function
bool isless (float x      , float y);bool isless (double x     , double y);bool isless (long double x, long double y);
Is less
Returns whether x is less than y.

If one or both arguments are NaN, the function returns false, but no FE_INVALID exception is raised (note that the expression x<y may raise such an exception in this case).

In C, this is implemented as a macro that returns an int value. The type of both x and y shall be float, double or long double.
In C++, it is implemented with function overloads for each floating-point type, each returning a bool value.

Parameters

x, y
Values to be compared.

Return value

The same as (x)<(y):
true (1) if x is less than y.
false (0) otherwise.

Example

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/* isless example */
#include <stdio.h>      /* printf */
#include <math.h>       /* isless, log */

int main ()
{
  double result;
  result = log (10.0);

  if (isless(result,0.0))
    printf ("log(10.0) is negative");
  else
    printf ("log(10.0) is not negative");

  return 0;
}

Output:

log(10.0) is not negative


See also

isgreater
Is greater (macro)
isgreaterequal
Is greater or equal (macro)
islessequal
Is less or equal (macro)
islessgreater
Is less or greater (macro)
isunordered
Is unordered (macro)