opAssign and references

[Nicolas Silva]

Hi,

I'm playing with variants and I noticed that opAssign is not invoked
when an assignation is done on a reference.

here is the test case:

import std.variant;

struct Foo
{
    Variant a;
    Variant b;
    ref Variant refA()
    {
        return a;
    }
}

void main()
{
    Foo f1;
    f1.a = 42; // ok
    f1.b = 23; // ok

    f1.refA() = 24; // Error: cannot implicitly convert expression
(24) of type int to VariantN!(maxSize)
    f1.refA().opAssign( 24 ); // ok, but not very nice...

    // slightly OT but
    Foo f2 = { a: 10 }; // Error: cannot implicitly convert expression
(10) of type int to VariantN!(maxSize)
}


Is it normal? Am I missing something?
I took Variant as an example because it does use opAssign but one
could create a struct defining opAssign with the same results.

More generally, I feel like I don't really understand the semantic of
opAssign (or maybe references). I'd intuitively expect it to be
invoked when the "=" operator is used on a reference and I'd also
expect it to be invoked in struct initializers (though there might be
something  about compiletime / runtime stories in this particular
case, yet i think one would expect it to just work).

D aims at being simple and intuitive, and in this case it looks not so
intuitive to me.

Best regards,

Nicolas Silva