CSE 333 Final Exam Flashcards

Smart Pointers

• Smart pointers manage memory and ensure automatic deallocation of pointers when they are no longer needed.
• Behave like regular pointers, supporting operator overloading for *, ->, and [].
• Automatically delete the associated heap-allocated object upon going out of scope.

unique_ptr

• A unique pointer that ensures exclusive ownership of a dynamically allocated object.
• Copy constructor and assignment operator are disabled to prevent multiple pointers from managing the same object.
• Can be transferred with std::move or reset using x.reset(y.release()) to change ownership.

shared_ptr

• Allows multiple pointers to own the same dynamically allocated object.
• Enables copying and assignment, incrementing a shared reference count with each copy.
• Reference count decreases when a shared_ptr is destroyed; if it reaches zero, the managed object is deleted.

Bugs from shared_ptr

• Issues arise when multiple shared_ptrs are created from the same raw pointer, leading to separate reference counts.
• If any shared_ptr decrements its count to zero, the managed object will be deleted, potentially leaving the other pointer as a dangling reference or causing double deletion.

weak_ptr

• Unlike shared_ptr, a weak pointer does not maintain a reference count, thus preventing circular references.
• Can only point to an object managed by a shared_ptr, and cannot be dereferenced directly.
• Commonly used in data structures like LinkedLists for "prev" pointers to simplify reference counting.

STL Map Container

• A container that stores key/value pairs, functioning like a hashmap.
• Access elements using iterators, with map.begin() and map.end() indicating the start and end of the map.
• Elements can be accessed via iterators with it.first for keys and it.second for values.

STL Vector Container

• Similar to an ArrayList, supporting dynamic resizing and element storage.
• Access elements using iterators, with vec.begin() indicating the first element and vec.end() indicating the end.
• Elements can be added using push_back() and accessed with vec.front() for the first and vec.back() for the last element.