toHash /opCmp for builtin-types

[Simon Buerger]

Following came to my mind while coding some generic collection 
classes: The toHash and opCmp operations are not supported for 
builtin-types though their implementation is trivial.

* toHash
The code is already there inside TypeInfo.getHash. But 
typeid(value).getHash(&value) is much uglier than value.toHash. Note 
that hashes make sense for integer (trivial implementation), not 
necessarily for floats.

* opCmp
Would be useful for delegating opCmp of a struct to one member. 
Alternative: Introduce new operator which returns 1/0/-1 (ruby does 
this with "<=>"). Currently I end up writing:

int opCmp(...)
{
     if(a>b) return +1;
     if(a==b) return 0;
     return -1;
}

which uses 2 comparisons where only 1 is needed (though the compiler 
might notice it if comparision is pure and so on).

Furthermore it might me a nice idea to have toString (or the future 
"writeTo") for builtin-types. It would need some new code in the 
core-lib, but could simplify generic programming.

any thoughts?

- Krox