Re: Can I return a reference to a string I just created?

From:
Robster <rob_marion1@yahoo.com>
Newsgroups:
comp.lang.c++.moderated
Date:
Mon, 23 Apr 2007 18:45:58 CST
Message-ID:
<1177364511.284249.327530@q75g2000hsh.googlegroups.com>
On Apr 23, 12:44 pm, ugnonim...@gmail.com wrote:

string& myFunc()
{
    string myString("some data");

    ....

    return myString;

}

When does the string I created get deleted? Is it the same as this:

string& myFunc2()
{
    return string("some other data");

}


Returning a reference is not a good idea, since, in this case, you are
returning a reference to a local object. The lifetime of a local
object ends with the termination of the method. If you do not return
by value, then a copy is made on the stack. If you wish to return by
reference, then you need to ensure that the object will not go out of
scope:

string& myFunc( string& someString )
{
  string* resultString;
  resultString = &someString;
  someString = "My, how I've changed.";
  return *resultString;
}

int main( )
{
  string aString( "Hi, I am a string." );
  cout << myFunc( aString ).c_str() << endl; // prints "My, how I've
changed."
  cout << aString.c_str() << endl; // prints "My, how
I've changed."

  return 0;
}

Robert Marion

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