When is it not a good idea to pass by reference?

Question

This is a memory allocation issue that I\'ve never really understood.

void unleashMonkeyFish()  
{  
    MonkeyFish * monkey_fish = new MonkeyFish();
    std::string          


        

Answer 1

Just to clarify the terminology, you've created MonkeyFish from the heap (using new) and localname on the stack.

Ok, so storing a reference to an object is perfectly legit, but obviously you must be aware of the scope of that object. Much easier to pass the string by reference, then copy to the class member variable. Unless the string is very large, or your performing this operation a lot (and I mean a lot, a lot) then there's really no need to worry.

Can you clarify exactly why you don't want to copy the string?

Edit

An alternative approach is to create a pool of MonkeyName objects. Each MonkeyName stores a pointer to a string. Then get a new MonkeyName by requesting one from the pool (sets the name on the internal string *). Now pass that into the class by reference and perform a straight pointer swap. Of course, the MonkayName object passed in is changed, but if it goes straight back into the pool, that won't make a difference. The only overhead is then the actual setting of the name when you get the MonkeyName from the pool.

... hope that made some sense :)