[Issue 8681] dmd accepts mutable AA key types for objects

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=8681

Marco Leise <Marco.Leise at gmx.de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |Marco.Leise at gmx.de

--- Comment #2 from Marco Leise <Marco.Leise at gmx.de> ---
(In reply to hsteoh from comment #1)
What works with the type system is to isolate the fields from C that define its
equality:

struct ImmutableCPart
{
    int x;

    size_t toHash() const {
        return typeid(int).getHash(x);
    }
    bool opEquals(const C c) const {
        return x == c.x;
    }
}

class C {
    immutable ImmutableCPart x;
    int y, z;

    this() { ... /* initialize x */ }
}

C[ImmutableCPart] lookup;

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