[Issue 17729] dmd says cast expression is "not an lvalue", but it can be used as one in other contexts

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=17729

er.krali at gmail.com changed:

           What    |Removed                     |Added
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                 CC|                            |er.krali at gmail.com

--- Comment #1 from er.krali at gmail.com ---
Furthermore, it doesn't work with ref parameters either:

---
struct S {
    int i;
}

void fun(ref S s, int i) {
    s.i = i;
}

void main() {
    shared S s;

    /* This fails:

       onlineapp.d(17): Error: function onlineapp.fun(ref S s, int i) is not
callable using argument types (S, int)
       onlineapp.d(17):        cannot pass rvalue argument cast(S)s of type S
to parameter ref S s

    fun(cast(S) s, 1);

    */

    (*(cast (S*) &s)).fun(1); // Nasty workaround
    assert (s.i == 1);
}
---

I also can't understand why the workaround works at all, the result of
dereferencing a pointer should surely be a rvalue?

Is that also a bug?

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