On 21.02.2011 21:22, Daniel Gibson wrote:
Am 21.02.2011 20:59, schrieb 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
Well, opCmp() can be done easier, at least for ints:
int opCmp(...) {
return a-b;
}
sadly no: (-3000000000) - (3000000000) = -170532704 which is
incorrect. It does however work for short/byte (and opCmp still
returning int).
For floats.. well, if you don't want/need any tolerance this would
work as well, else it'd be more difficult.
I'm not sure if it make sense for floats. Furthermore, does
TypeInfo.getHash support them?
A <=> operator would be neat, though.
