Bug 21094 – [REG2.078] Array equality for struct with class member and opCast and alias this

This testcase does not compile since 2.078: ``` class C { int a; } struct S { bool isValid; C fib; inout(C) get() pure @safe @nogc nothrow inout { return isValid ? fib : C.init; } T opCast(T : C)() const { return null; } alias get this; } auto foo(S[] lhs, S[] rhs) { return lhs == rhs; } ``` The error: /druntime/src/core/internal/array/equality.d(101): Error: template instance `opCast!(Object)` does not match template declaration `opCast(T : C)()` /druntime/src/core/internal/array/equality.d(101): Error: template instance `opCast!(Object)` does not match template declaration `opCast(T : C)()` /druntime/src/core/internal/array/equality.d(102): Error: template instance `opCast!bool` does not match template declaration `opCast(T : C)()` /druntime/src/core/internal/array/equality.d(102): Error: template instance `opCast!(Object)` does not match template declaration `opCast(T : C)()` weka/lib/comparison.d(38): Error: template instance `core.internal.array.equality.__equals!(S, S)` error instantiating It appears to be fixed by https://github.com/dlang/druntime/pull/3142 , but please add this extra testcase. Thanks.

dlang/dmd pull request #14379 "Add test case for issue 21094" was merged into master: - efa069f93274011db774cde1ffc18acd8c259619 by RazvanN7: Add test case for issue 21094 https://github.com/dlang/dmd/pull/14379

Test was added. Closing this.