[Issue 23738] New: A function accepting an alias of a type member requires static

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=23738

          Issue ID: 23738
           Summary: A function accepting an alias of a type member
                    requires static
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Keywords: diagnostic, rejects-valid
          Severity: normal
          Priority: P1
         Component: dmd
          Assignee: nobody at puremagic.com
          Reporter: schveiguy at gmail.com

Consider the following complete file:

```d
struct S
{
    int t;
}

static void foo(alias F)()
{
}

void bar(alias F)()
{
}

void main()
{
    foo!(S.t);
    bar!(S.t); // Error: need `this` for `bar` of type `pure nothrow @nogc
@safe void()`
}
```

The call to `foo` succeeds, whereas the call to `bar` fails. The `static`
storage class for a function at module level should be a no-op, but somehow
it's affecting compilation. I believe both should succeed (taking an alias to a
member without actually using the member, e.g. for introspection, is valid),
though it's also worth investigating why `static` affects this function.

See relevant thread, apparently an unreported bug since 2013:
https://forum.dlang.org/post/simvgcbylmisvdlilxev@forum.dlang.org

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