How Can I Correctly Push a `std::unique_ptr` into a `std::vector`?

Unable to Push Back Unique_Ptr into a Vector

The provided code attempts to push a std::unique_ptr into a vector, which results in a compilation error due to the inability of performing a copy operation on the unique pointer.

Recall that std::unique_ptr ensures exclusive ownership of the contained pointer to a specific object. This means that when assigning a unique pointer, the ownership is moved and not copied. Consequently, making copies of a unique pointer is prohibited as multiple owners would violate its unique ownership guarantee.

To resolve the issue and push the unique pointer into the vector correctly, use the std::move function as follows:

vec.push_back(std::move(ptr2x));

std::move transfers the ownership of the unique pointer to the vector, enabling its insertion into the vector without violating the unique ownership rule.

It's crucial to note that the initial usage of std::unique_ptr in this code is incorrect. It attempts to manage a pointer to a local variable, which contradicts the required control over the object's lifetime. To prevent this discrepancy, allocate the object dynamically using, for instance:

std::unique_ptr<int> ptr(new int(1));

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