# C++

• unique_ptr, shared_ptr and weak_ptr: introduced in c++11, defined in <memory>. They are all containers of a raw pointer.

• auto_ptr introduced in c++11, deprecated/removed in c++17.

• unique_ptr: Container of a owned raw pointer; does NOT allow copy but supports std::move which transfers ownership.

• shared_ptr implements reference counting. Can be copied. The referenced object will be destroyed when and only when all copies of the shared_ptr have been destroyed

• weak_ptr: is created as a copy of a shared_ptr, which has no effect on the shared_ptr or its other copies. After all copies of a shared_ptr have been destoyed, all weak_ptr copies become empty

# references

• https://en.wikipedia.org/wiki/Smart_pointe