TDPL: Manual invocation of destructor

[F. Almeida]

== Quote from Andrei Alexandrescu (SeeWebsiteForEmail at erdani.org)'s
article
> Jonathan M Davis wrote:
> > On Monday, August 09, 2010 16:40:23 Andrei Alexandrescu wrote:
> >> class File {
> >>      FILE * fp;
> >>      this() { fp = fopen("/tmp/temporary"); }
> >>      ~this() { fclose(fp); }
> >> }
> >>
> >> The destructor does not test fp because it assumes it was
opened.
> >>
> >> Interestingly enough, by TDPL the code above is in fact invalid
already.
> >> TDPL mentions that an object's lifetime starts as soon as it's
been
> >> branded, which is before default construction. As a direct
consequence,
> >> the destructor should be able to deal with an object stamped
with all
> >> init values for all fields - in this case a null fp.
> >
> > I would take that as an argument for making clear() set the
object in the state
> > prior to the constructor call.
> [snip]
> I agree. Do others?
> Andrei

A clear() that leaves the object in the initial (not constructed)
state is the most sensible choice.
This is good for two reasons: 1. it avoids useless resources
reallocation and 2. it leaves the destroyed object in a (somewhat)
safe and identifiable state.
One could easily make his own reset() function that calls clear()
and then the constructor, if needed.