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From: ark@alice.UUCP (Andrew Koenig)
Newsgroups: comp.lang.c++
Subject: Re: Calling constructors explicitly
Message-ID: <8957@alice.UUCP>
Date: 24 Feb 89 04:23:28 GMT
References: <8102@paris.ics.uci.edu>
Organization: AT&T Bell Laboratories, Liberty Corner NJ
Lines: 26

In article <8102@paris.ics.uci.edu>, schmidt@siam.ics.uci.edu (Doug Schmidt) writes:

> Apparently, cfront 2.0 also exhibits the same behavior.  Would someone
> please tell me whether this is a bug or a feature, i.e., is it part of
> the language definition that constructors must not be called
> explicitly?

It's a feature.

When I define a constructor, I should be entitled to assume that
the constructor is initializing newly allocated storage -- that is,
that there are no prior values in the object being constructed
that I might have to preserve.

That entitlement vanishes if it is possible to construct a given
object more than once.

Notwithstanding the above, there are arcane circumstances in which
one may want to call a constructor explicitly.  Should one ever be
allowed to do so, it would be in circumstances where the caller would
be expected to take responsibility for doing it only in the case
where the object is not already constructed.  C++ is not a completely
safe language.
-- 
				--Andrew Koenig
				  ark@europa.att.com