...i ) { }

   // must succeed
   if ( pi == NULL ) { }

   // must succeed
   if ( NULL == pi ) { }

   // must succeed
   if ( mfp...

...atan2 function:

    atan2(0, -0) => pi
    atan2(-0, -0) => -pi

pow() is also sensitive to...

...from C into D, it's not needed for compatibility.

cos(PI) + sin(PI) *1i;

...C99 and for situations like

cos(PI) + I * sin(PI)

where you want to convert...

...succeeds (pointer):
   if ( pi == NULL_v() ) { }

   // Ok: succeeds (pointer):
   if ( NULL_v() == pi ) { }

   // Ok: succeeds...

...what you expect. For example, sin(2*PI) will not be <i>exactly<i> zero...

...and a point suffices:

`sin.pi' instead of `sin( pi)'
`arr.1'  instead of `arr...

...since they are all simple relationships on pi?  These do provide an important purpose: they...

...10)
  max!(double)(10, 33.33, -PI, 2*PI, 0);
  int[] nums = ...;
  int bound = max...

...PI+x.epsilon) and sin(n*PI-x.epsilon), if
  n*PI + PI >= n*PI...