• via Digitalmars-d-bugs (32/32) Apr 10 2015 https://issues.dlang.org/show_bug.cgi?id=14438

via Digitalmars-d-bugs <digitalmars-d-bugs puremagic.com> writes:

https://issues.dlang.org/show_bug.cgi?id=14438

          Issue ID: 14438
           Summary: is(A P == super) (tuple of supertypes) should work
                    with structs and alias this
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: DMD
          Assignee: nobody puremagic.com
          Reporter: andrei erdani.com

Currently D offers a means to get all supertypes (base class and implemented
interfaces) of a class types with this construct:

static if (is(C P == super))
{
}

Inside the static if, P is a tuple starting with the base class and continuing
with all implemented interfaces, in lexical order.

Now consider:

struct S(T)
{
    private T datum;
    T fun() { return datum; }
    alias fun this;
}

There is no introspection mechanism that, given S, finds T. There should be
one, and it should work with the upcoming multiple alias this.

I think it's fine if we use the same syntax.

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