C++ return value created before or after auto var destruction?

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Yes, the auto variable will remain in scope until after the return is finished. This is especially true if you are using a compiler that optimizes the return, eg:

Gift get() 
{ 
    Lock lock(mutex);
    return gift;
} 

Gift g = basket.get();

Which would be equivilent to this sequence:

Gift g;
Lock lock(mutex);
g = Gift(gift);
lock.~Lock();

May be optimized to act more like this:

void get(Gift &ret) 
{ 
    Lock lock(mutex);
    ret = gift;
} 

Gift g;
basket.get(g);

Which would be equivilent to this sequence:

Gift g;
Lock lock(mutex);
g = gift;
lock.~Lock();

In other words, a temporary can be removed during the return.

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