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Returning an object from a function

Posted on 2014-01-23
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Last Modified: 2014-01-23
I am a bit confuse with object return in general. Am I right the copy constructor being called for the object when a function return the object.

For example,

std::string ReturnStringFunction (std::string str)
{
    std::string s = str;
    return s;
}

Now in the main program

main()
{
       std::string s1;
       std::string s2;
       s1 = ReturnStringFunction ("DummyString1");
       s1 = ReturnStringFunction ("Dummy2");
       // ??? am I protentially introduce a memory leak here?

       s2 = ReturnStringFunction ("Dummy2");
       // ??? am I introduce a different copy of "Dummy2", 2 different memory location.


}
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Question by:tommym121
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2 Comments
 
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Accepted Solution

by:
jkr earned 2000 total points
ID: 39805087
No, no memory leaks will occur in the above. The assignment operator for a 'std::string' will dispose and clean up any allocated memory before storing the new contents. 's' will be cleaned up when 'ReturnStringFunction()' exits.
And yes, "Dummy2" will be stored in two string objects, both of which will allocate the memory on the process' heap.
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Author Closing Comment

by:tommym121
ID: 39805167
Thanks.
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