Force deleting std::shared_ptr in C++

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According to the first answer in this article: Explicitly deleting a shared_ptr

Is it possible to force delete a std::shared_ptr and the object it manages like below code?

do {     ptr.reset(); } while (!ptr.unique());  ptr.reset();  // To eliminate the last reference 

Technically, this should try calling std::shared_ptr::reset if the pointer has more than 1 reference count, unless it reaches to one. Any thoughts on this?

 


This code doesn't make any sense.

Once you reset ptr, it doesn't manage an object anymore. If ptr was the only shared_ptr sharing ownership, then you're done. If it wasn't... well, you don't have access to all those other ones. Calling reset() on a disengaged shared_ptr is effectively a noop - there's nothing more to reset.

Imagine a simple scenario:

std::shared_ptr<int> a = std::make_shared<int>(42); std::shared_ptr<int> b = a; // a and b are sharing ownership of an int  do {     a.reset(); } while (!a.unique()); 

The only way to reset b is to reset b - this code will reset a only, it cannot possibly reach b.

Also note that unique() was deprecated in C++17 and is removed entirely in C++20. But if even if you use use_count() instead, once you do a.reset(), a.use_count() will be equal to 0 because a no longer points to an object.

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