Revamping associative arrays

[bearophile]

Max Samukha:

> I agree. But the problem is the lack of a decent way to instantiate an
> empty AA. Now you either have to do idiotic things like:
> 
> int[int] a;
> a[1] = 1;
> a.remove(1);
> 
> Or wrap the array in another type.

This is an empty AA, you need nothing else:
int[int] a;

In my post I have also said I'd like to have a built-in expression literal for empty AA, I use this in my dlibs:

private template AA_impl(KeyType, ValueType) {
    ValueType[KeyType] result;
    const ValueType[KeyType] res = result;
}
template AA(KeyType, ValueType) {
    const ValueType[KeyType] AA = AA_impl!(KeyType, ValueType).res;
}

That you can use for example like this, to give an empty AA to a foo() function:
foo(AA!(int, float));

Something built-in with a better syntax may be found, example:

That can be used like:
foo([int:float]);

Bye,
bearophile