• Heinz Saathoff <hsaat despammed.com> Sep 08 2005
• "Walter Bright" <newshound digitalmars.com> Sep 08 2005
• Heinz Saathoff <hsaat despammed.com> Sep 08 2005

Hello,

I just had a look at math.h and found the macros for isgreater, isless 
and some others. The definition of isgreater is

  #define isgreater(x,y)   !((x) !> (y))

Are these !op comparison operators DMC-extension (I didn't find any 
reference to these elsewhere)? It seems that !op negates the result of 
the comparison, so that

    a !> b    is the same as    !(a > b)

Is this right? If so, why have you extended the standard operators?


- Heinz

"Heinz Saathoff" <hsaat despammed.com> wrote in message
news:MPG.1d8a0089f315b39d9896f1 news.digitalmars.com...
 I just had a look at math.h and found the macros for isgreater, isless
 and some others. The definition of isgreater is

   #define isgreater(x,y)   !((x) !> (y))

 Are these !op comparison operators DMC-extension (I didn't find any
 reference to these elsewhere)? It seems that !op negates the result of
 the comparison, so that

     a !> b    is the same as    !(a > b)

 Is this right?


Yes.

 If so, why have you extended the standard operators?


Back around 1990 or so, there was a group called NCEG (Numerical C
Extensions Group) that was interested in fixing C's deficiencies at
numerical computing. They produced an excellent proposal for doing this, and
I implemented all of it. Unfortunately for C, it was never adopted by the C
standard, though parts of it did find their way into the C99 standard.

You can find the documentation for them at
www.digitalmars.com/ctg/ctgNumerics.html

Walter Bright schrieb...
 I just had a look at math.h and found the macros for isgreater, isless
 and some others. The definition of isgreater is

   #define isgreater(x,y)   !((x) !> (y))

 Are these !op comparison operators DMC-extension (I didn't find any
 reference to these elsewhere)? It seems that !op negates the result of
 the comparison, so that

     a !> b    is the same as    !(a > b)

 Is this right?


 Yes.
 
 If so, why have you extended the standard operators?


 Back around 1990 or so, there was a group called NCEG (Numerical C
 Extensions Group) that was interested in fixing C's deficiencies at
 numerical computing. They produced an excellent proposal for doing this, and
 I implemented all of it. Unfortunately for C, it was never adopted by the C
 standard, though parts of it did find their way into the C99 standard.
 
 You can find the documentation for them at
 www.digitalmars.com/ctg/ctgNumerics.html


Thanks. I will have a look on that article.


- Heinz