Re: return a reference

From:
"Alf P. Steinbach" <alfps@start.no>
Newsgroups:
comp.lang.c++
Date:
Fri, 30 Nov 2007 17:54:58 +0100
Message-ID:
<13l0g376n00i9ea@corp.supernews.com>
* emannion@gmail.com:

I am trying to clear up some reference questions

if I have a function that returns a reference to an int will that data
be lost when the function goes out of scope

 int& retRef()
 {
     int j=10;

     return j;
 }


Undefined behavior where the reference is used by the caller.

int main()
{

    int& k = retRef();

    int l = k;

    return 0;
}

k is set to 10 after retRef() is called from main, I thought this
would not be possible if retRef() goes out of scope.


Undefined behavior includes that the program may produce what you
erronously expect.

In practical terms, for a typical C++ implementation you have a
reference to a location on the stack, and that location has not been
reused (it could be reused by a simple expression evaluation).

Cheers, & hth.,

- Alf

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