On 5 February 2015 at 21:52, Levi Morrison <[email protected]> wrote:
> To chime in regarding allowing contravariant parameter types: I
> struggle to find use cases for it.
Theoretically it would allow a class to implement two separate
interfaces that would otherwise be incompatible:
interface A {
function foo();
}
interface B implements A {
function bar(B $b);
}
interface C implements A {
function bar(C $c);
};
class D implements B, C {
// Any object that implements B or C must also
// implement A, but only the methods from interface A
// are safe to call inside the method.
function bar(A $a){
$a->foo();
}
function foo(){...}
}
But I agree, the number of times I've wanted to do this is low.
cheers
Dan
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