When does std::shared_ptr release its object?

Question

I'm on Ubuntu 14.04 using GCC 4.8.4 and I have code similar to the following:

std::shared_ptr<MyClass> my_shared_object = set elsewhere...
MyFunction(*my_shared_object);

Where MyFunction's signature looks like this:

void MyFunction(const MyClass& my_object)

The full code can be found here

However, I am finding that my_object actually goes out of scope within the context of MyFunction. My thought was that the my_shared_object will only release its contents once it goes out of scope, meaning after the MyFunction has returned. I am not sure if I am either misunderstanding std::shared_ptr or if maybe this is a GCC bug.

I guess the question boils down to: when I dereference a std::shared_ptr, does that guarantee that the std::shared_ptr will persist as long as the dereference is being used?

Answer 1

Whatever is managed by a std::shared_ptr will be destroyed the moment there's no std::shared_ptr left asserting a claim, all other ways to refer to it are irrelevant.

And local variables are only destroyed upon leaving the respective scope. Dereferencing a std::shared_ptr does not modify it in any way.