On Wednesday, 29 May 2013 at 12:36:19 UTC, Jakob Ovrum wrote:
I need to be able to catch an exception that may have been
thrown during the initialization of `i`, but still have `i` be
const. I can't omit the variable because I *don't* want to
accidentally catch anything that transform() may have thrown.
Note that the simple type const(int) is an example. This is
actually in highly generic code and the type may have mutable
indirection.
Fundamental issue here is that
const T t;
is almost useless, it is essentially immutable since you cannot
change it and you cannot alias it. As such, it probably should be
changed to a mutable object or an immutable one.
However, since const/mutable aliasing is allowed, you can do:
union U (T)
{
const T ct;
T mt;
}
because const doesn't mean that object would never change, you
can mutate it through alias. From the opposite view, there is
also no problem in reinterpeting a mutable object as const object
(since mutables can be converted to const).
Depending on your mutable indirection situation this can work or
may not.
