Why D const is annoying

[Chris Cain]

On Wednesday, 2 May 2012 at 04:18:18 UTC, Chris Cain wrote:
> ... specify that one of those students has a read-only 
> connection. Something like Student!StudentDBConnection might 
> work, and then maybe Student!const(StudentDBConnection).

I take the second one back, I've not written any kind of 
connection code before, but it occurs to me that 
StudentDBConnection must have some kind of mutable state in order 
to connect to something.

Maybe a ROConnection object (or a struct and use the awesomeness 
of D's compile-time duck typing) or something along those lines?