Associative array bug?

[BCS]

Bruno Medeiros wrote:
[...]
> 
> Now, whether interfaces can be used as AA keys or not, it depends if we 
> have a method to do hash from an interface. One way would be to require 
> the interface to have a toHash method. But I'm not sure if that would 
> make much sense.
> Another way, perhaps the most sensible, would be to cast to Object and 
> use the underlying toHash(). But that depends on whether it is allowed 
> that an interface can be converted to a reference to it's underlying class.
> The doc only says "A class that implements an interface can be converted 
> to a reference to that interface.", but not the otherwise. However it 
> seems that DMD does allow for an interface to be converted to a class 
> (since that feature is what allows interface->class return type 
> covariance to work), but that is all very not explicit and not documented.
> 
> 
> 
> 
How about using an IndexForAA interface and a mixin template to pull up 
the right symbols. Then all that would be need would be to have the 
interface inherent that interface and away you go.


// i'm working from memory here so

interface KeyForAA
{
	uint toHash();
	int opCmp(KeyForAA);
}

template KeyForAA_Mixin
{
		// pull in the defaults from Object or the super class
	alias toHash toHash;
	alias opCmp opCmp;
}