self-referential invariant member

[Neil Vice]

I am attempting to provide a constant instance of a struct as a member of 
the struct (in 2.010) and am getting unexpected compiler errors. Can someone 
explain what the compiler thinks I'm trying to do here and/or how I'd go 
about achieving what I want if it's possible?

The following code:

    struct Test
    {
        public invariant Test Default;
    }

    void main()
    {
        Test test = Test.Default;
    }

produces the following compiler output:

    test.d(3): struct test.Test unable to resolve forward reference in 
definition

Similarly if Test is declared as a class not a struct the compiler produces 
the following:

    test.d(9): Error: 'this' is only allowed in non-static member functions, 
not main
    test.d(9): Error: this for Default needs to be type Test not type int
    test.d(9): Error: cannot implicitly convert expression (this.Default) of 
type invariant(Test) to test.Test

If Default is declared as a manifest constant using the enum keyword the 
compiler gets a stack overflow (bug #1800).

If I attempt to initialise Default (where Test is a struct), the compiler 
makes reference to opCall:

    public invariant Test Default = {};

yields:

    test.d(9): Error: no property 'opCall' for type 'Test'
    test.d(9): Error: function expected before (), not 1 of type int
    test.d(9): Error: cannot implicitly convert expression (1(Default)) of 
type int to Test