Incomplete knowledge + all powerful casts = troubles

[Trass3r]

> Unfortunately now the code contains a small bug. The cast now converts  
> const(int)->uint, and foo() will modify a const value, that gives  
> undefined effects in D2.

I get the point, but in this particular case it's not a real bug since foo  
doesn't take it by ref.
The int is copied anyways, no matter if the source is const or not.

I'm not sure how the actual problem should be solved though...

> const(int) x;
> auto y = cast(uint)x;
> static assert(is(typeof(y) == const(uint)));

...cause this doesn't look right either, cause it silently keeps the const.
Imagine x being unapparently const and you pass y to some function or  
template that doesn't allow const.
You get an abstruse error message and don't really know why it happened  
cause you think y is just a uint.

Maybe stripping away constness should be a special case that can't be  
combined with a normal cast, i.e. only 'cast()' can do it.