Stewart Gordon <smjg_1998@yahoo.com> wrote in news:dd3cea$26u7$1@digitaldaemon.com

[...]
> But there seems to be room for debate on what the best solution is. Possibilities:
> 
> 1. State in the spec that it is an incorrect practice to define opCmp to return 0 if opEquals returns true.
[...]

Introducing alternative 4:

Redesign of overloading operators.

1. In case of singletons also an `opEqual' is senseless and should be accompanied by an implementation with an `assert( 0);'

2. When an `opEqual' makes sense, then it is so basic, that it should be executed prior to the other cases except for performance reasons.

2.a. Therefore an `opNotEqual' should accompany the `opEqual' and the `opCmp' should be synthesized from both along the line:

   eq= opEqual();
   if( eq) return 0;
   neq= opNotEqual();
   if( eq != neq)
     return neq;
   else
     throw new Exception( "Aequivalence not allowed");

2.b. If the above template is not suitable out of performance reasons
the `opCmp' should not be synthesized and replaced by the definition
of an `opCmpPerf'. Its then up to the adult programmer to assure the
consistency of the design.

-manfred