short circuited expressions...

Steven Wong

Just wondering, is it portable to write:

something* pSomething = getSomething();

if( pSomething && pSomething->stuff() ) {

....

}

I'm not sure if the condition statement is always shortcircuited for
every implementation of C++?

TIA

Jul 19 '05 #1

Subscribe Reply

3805

Julián Albo

Steven Wong escribió:

I'm not sure if the condition statement is always shortcircuited for
every implementation of C++?

It is. Your C++ manual don't say that? Find another.

Regards.

Jul 19 '05 #2

Mike Wahler

"Steven Wong" <gn*******@yaho o.com> wrote in message
news:a7******** *************** ***@posting.goo gle.com...

Just wondering, is it portable to write:

something* pSomething = getSomething();

if( pSomething && pSomething->stuff() ) {

...

}

I'm not sure if the condition statement is always shortcircuited for
every implementation of C++?

The language standard dicates that it must. However, there's
no possible way it can actually enforce this rule. An implementation
that does not obey it is not conforming, and imo should not be used.

-Mike

Jul 19 '05 #3

Jerry Coffin

In article <a7************ **************@ posting.google. com>, gndm_2001
@yahoo.com says...

Just wondering, is it portable to write:

something* pSomething = getSomething();

if( pSomething && pSomething->stuff() ) {

...

}

I'm not sure if the condition statement is always shortcircuited for
every implementation of C++?

Yes it is, UNLESS you've overloaded operator&& for the types involved.

If you have something that doesn't short-circuit evaluations like this,
it's not C++ and not really even much like C++ (or C) either -- if I'm
not mistaken, short circuit evaluation has been been part of C since
before the beginning (i.e. back at least as far as B, and quite possibly
to BCPL or even CPL).

--
Later,
Jerry.

The universe is a figment of its own imagination.

Jul 19 '05 #4

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