[Issue 17766] Wrong choice of generic mutable/const/immutable methods

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=17766

alexandru.ermicioi at gmail.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |alexandru.ermicioi at gmail.co
                   |                            |m

--- Comment #1 from alexandru.ermicioi at gmail.com ---
This is not the only case, here is another case of wrong selection:

----------------------
class Mquartz(T, Z) {
    Z pass(T component) const {
        "Mutable pass".writeln;
        return component.z;
    }
    const(Z) pass(const T component) const {
        "Const pass".writeln;
        return component.z;
    }
    const(Z) pass(immutable T component) const {
        "Immutable pass".writeln;
        return component.z;
    }
    const(Z) pass(inout T component) const {
        "Inout pass".writeln;
        return component.z;
    }
}

struct V {
    int z;
}

void main() {

    auto m = new Mquartz!(V, typeof(V.z));

    // V v = V(21);
    // writeln(m.pass(v));
    writeln(m.pass(V(20)));
    writeln(m.pass(const(V)(20)));
    writeln(m.pass(immutable(V)(20)));
    writeln(m.pass(inout(V)(20)));
}
-------------------------
Current logic will select only const version with const argument instead of
selecting right ones:
-------------------------
Const pass
20
Const pass
20
Const pass
20
Const pass
20
-------------------------
The overload selection logic works as expected only if m is const, then
response will as expected:
-------------------------
Mutable pass
20
Const pass
20
Immutable pass
20
Inout pass
20
-------------------------

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