How to override opCmp when two different sorts are needed?

[Jarrett Billingsley]

"John Bartelt" <bartelt at cox.net> wrote in message 
news:f9quel$rou$1 at digitalmars.com...
>I have a class that contains two variables. Sometimes I need to sort an 
>array of the class based on variable 1, and later in the same progam sort 
>the array based on variable 2.
>
> Can someone give me an idea of how to do this (smartly, efficiently, 
> cleverly, polymorphically, ...)?
>
> Best idea that I've had so far is to use a static flag in the class to 
> indicate which sort is desired, and then to have the overloaded opCmp() 
> check the flag before comparing.

Write your own sort routine which takes a given predicate.  :\

Tango provides such a routine in tango.core.Array; phobos provides no such 
analogue.  With phobos, either write your own routine, or use 
std.c.stdlib.qsort.  I'll let you decide which is more elegant.