Re: Returning a reference from a function.

From:

"Alf P. Steinbach" <alfps@start.no>

Newsgroups:

comp.lang.c++

Date:

Thu, 12 Jul 2007 17:07:26 +0200

Message-ID:

<139cgtgg9nvch6f@corp.supernews.com>

* Lionel B:

On Thu, 12 Jul 2007 17:09:47 +0300, Juha Nieminen wrote:

(snipped context restored)

Lionel B wrote:

Of course it's also *possible* (i.e. permitted by the language) - but
quite likely disastrous! - if the returned reference *is* to a local
object:

int& foo()
{
int a;
return a;
}

int main()
{
}

$ g++ -std=c++98 -pedantic scratch.cpp scratch.cpp: In function ?int&
foo()?: scratch.cpp:3: warning: reference to local variable ?a?
returned

(note warning, but no error).

Why is it not an error?

Because the Standard says it's not. I can't think off the top of my head
a valid scenario for doing this (no doubt someone here can...),

Well, one usage is to compute a stack pointer. Which might be used to
decide whether some object is allocated on the stack or not. Conceivably...

but there
you go... C++ is renowned for supplying plenty of rope to hang yourself.

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