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

 

[=?iso-8859-1?Q?Juli=E1n?= 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.

 

[Mike Wahler]

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

 

[Jerry Coffin]

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).