Fun with templates

[TommiT]

On Saturday, 6 July 2013 at 23:11:26 UTC, Manu wrote:
> [..] I feel like it would be a much cleaner solution than any of
> the others presented in this thread...

I think Artur's solution is the cleanest one because it changes 
the default behaviour to a more sensible one: it is useful to 
keep the full type information only if the type isn't implicitly 
convertible from immutable to mutable and back again... otherwise 
keeping the full type information along only causes inconvenience.