Is there a way to remove the requirement for parenthesis?

[Charles Hixson]

In this test I'm trying to emulate how I want a typedef to act, but I 
run into a problem:

import   std.stdio;

struct   BlockNum
{  uint   value;

    uint   opCast()   {   return   value;   }
    void   opAssign (uint val)   {   value = val;   }
    uint   opCall()   {   return   value;   }
}

void   main()
{  BlockNum   test;
    test   =   42;
    uint   tst2   =   test();  // <<== if I don't have the parenthesis I
                               //    get a compiler error (cast
                               //    required).
           //  kfile.d(15): Error: cannot implicitly convert expression
           //          (test) of type BlockNum to uint

    writef ("tst2 = %d\n", tst2);
}

It seemed to me as if the parens shouldn't be required here, but I seem 
mistaken.  Which leads to ugly code.  Is there a way around this?