Re: strange crash after assertion with std::map::iterator

From:

Ulrich Eckhardt <eckhardt@satorlaser.com>

Newsgroups:

microsoft.public.vc.stl

Date:

Tue, 24 Apr 2007 10:06:56 +0200

Message-ID:

<1eq0g4-mq.ln1@satorlaser.homedns.org>

Duane Hebert wrote:

"Mycroft Holmes" <m.holmes@nospam.it> wrote in message
news:OdtFpnZhHHA.4140@TK2MSFTNGP05.phx.gbl...

nope, you missed my point:
map::iterator CANNOT be a primitive type, so my original example
is totally equivalent to calling the default constructor, or if
you prefer:

T x = T();

if you replace T with int, x will be zero.

I guess I'm still missing your point. Just because a
type is not primitive, you're saying that it automatically
uses default construction? So given some user defined
type foo,

saying foo f; is equivalent to saying foo f = foo(); ?

Hmm, consider string or vector, you surely would expect them to be properly
initialised so that using them doesn't cause UB. Expecting the same for
iterators is surely understandable.

However, the STL was designed for performance but making a
default-constructed iterator equal to the end iterator imposes a
significant overhead. Therefore it simply is not done.

Uli