Property discussion wrap-up

[Zach the Mystic]

Steven Schveighoffer had mentioned the interesting point that you 
may want *mandate* the use of parentheses. This is easily 
solvable with another opXXX function, which I name opDo. Just to 
illustrate with ordinary structs:

struct Foo
{
   int opDo() { return 4; }
}
Foo foo;

foo; // Error: a struct with opDo must be called with parentheses