On 5 February 2015 at 21:52, Levi Morrison <le...@php.net> 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 -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php