Sean Kelly wrote:
> Bill Baxter wrote:
>> Is there a generic 'max' function anywhere in phobos?
>> The closest I could find was std.math.fmax().
> 
> Not that works for all input types, as far as I know.  However, something like the code below should work.  This is off the top of my head so it may have bugs, but it's a general idea of what such a template function may need to do.
> 
> /**
>  * Returns the largest of the two supplied types, or the first type if
>  * the sizes are identical.  If either type is an object then both must
>  * be objects of either the same type or where one is a base class of
>  * the other.  Interfaces are not supported.
>  */
> template largestOrConvertible( T, U )
> {
>     static if( is( T : Object ) || is( U : Object ) )
>     {
>         static assert( is( T : Object ) && is( U : Object ),
>                        "Types incompatible." );
> 
>         static if( T : U )
>             alias T largestOrConvertible;
>         else static if( U : T )
>             alias U largestOrConvertible;
>         else static assert( false, "Object types must be related." );
>     }
>     else static if( is( T : Interface ) || is( U : Interface ) )
>         static assert( false, "Interface types not yet supported." );
>     else static if( T.sizeof < U.sizeof )
>         alias U largestOf;  // concrete type, U larger
>     else alias T largestOf; // concrete type, T larger or equal
> }
> 
> template max( T, U )
> {
>     largestOrConvertible!(T,U) max( T t, U u )
>     {
>         return t > u ? t : u;
>     }
> }
> 
> template min( T, U )
> {
>     largestOrConvertible!(T,U) min( T t, U u )
>     {
>         return t < u ? t : u;
>     }
> }
We could do all of this code, or we could just have type inference for return values:

auto max (T, U) (T t, U u)
{
  return t > u ? t : u;
}

Problem solved!

== Quote from John Reimer (terminal.node@gmail.com)'s article
> On Wed, 08 Nov 2006 05:48:58 -0800, Sean Kelly <sean@f4.ca>
wrote:
> > David Qualls wrote:
> >> After looking at the mass of code it takes to implement a
> >> simple generic max() or min() function in D, I'm really
> >> starting to pine
> >> for my C preprocessor...

> Blech!  I do not find C/C++ macros readable!
...
> Oh... that feels better.  It seems I periodically have to bash
> the CPP...
> at least once a year, at least. :)
> -JJR

Well, since I was the one that brought it up, I feel I deserve payment for the positive psycho-therapy you just experienced!

  ;-)

David

"Reiner Pope" <reiner.pope@REMOVE.THIS.gmail.com> wrote in message news:ejbpi0$194t$1@digitaldaemon.com...

> We could do all of this code, or we could just have type inference for return values:
>
> auto max (T, U) (T t, U u)
> {
>   return t > u ? t : u;
> }
>
> Problem solved!

That's true.  D already does return type deduction for delegate literals..

LOL!

Well, I hope you don't charge too much! :D

-JJR