Containers

sequence containers

provides access to sequences of elements. includes:

• std::vector<T> elements stored in continueous memory
• std::deque<T> elements don't stored in continueous memory
• std::list<T>
• std::array<T>
• std::forward_list<T>

deques support fast push_front operations. However, for other common operations like element access, vector will always outperform a deque.
deque slower to access middle elements, however.

vector is the type of sequence that should be used by default... deque is the data structure of choice when most insertions and deletions take place at the beginning or at the end of the sequences.

Uniform initialization.

container adaptors

associative containers & iterators

have no idea of a sequence
data is accessed using the key instead of indexes.
includes:

• std::map<T1, T2>
• std::set<T>
• std::unordered_map<T1, T2>
• std::unordered_set<T>

Iterators let us view a non-linear colleciton in a linear manner
auto elems.end() does not point anything in the elems, it point to the last element + 1, so it out of the container

container adaptors

• std::queue

  the class template acts as a wrapper to the underlying container - only a specific set of functions is provided. The queue pushes the elements on the back of the underlying container and pops them from the front.

• std::stack

  the class template acts as a wrapper to the underlying container - only a specific set of functions is provided. The stack pushes and pops the element from the back of the underlying container, known as the top of the stack.