Hi Everyone ✋

In this tutorial series we will talk about C++ STL in depth.

STL stands for Standard Template Library.

STL has four components

Containers

Iterators

Algorithms

Function Objects

Containers

Containers are actually pre implemented data structures provided by C++ to use. These containers help us to write code efficiently without worrying about data structure implementation explicitly.

Containtainers can be divided in two parts mainly

- - - - Sequential Containers
      - Non-Sequential Containers

Sequential Containers

Sequential containers grow sequentially.

- - - - Vector
      - List
      - Array
      - Deque
      - Forward List
      - Stack
      - Queue
      - Priority Queue

Non-Sequential containers

Non-Sequential containers grow arbitrarily.
Non-Sequential containers can be divided into two parts also

- - - - Associative Containers
      - Unordered Associative Containers

Associative containers

Associative containers are sorted collections of data. Each element of an associative container is inserted in a sorted manner. Associative containers are –

- - - - Set
      - Multiset
      - Map
      - Multimap

Unordered associative containers

Unordered associative containers are unsorted collections of data. But unordered associative containers provide random access to each element which is really effective. Unordered associative containers are –

- - - - Unordered_set
      - Unorodered_multiset
      - Unordered_map
      - Unordered_multimap

Iterators

Iterators are mainly pointers of STL containers. Iterators are used to access the memory locations of STL containers. With the help of the iterator we can traverse any STL container easily. Iterators can be incremented and decremented.

it++, Incremented, After incremented it points to the next element in the current container

it−−, Decremented, After decrementing it points to the previous element in the current container

Algorithms

Algorithms in C++ are specially designed to be used on ranges of elements. Algorithms in C++ are a collection of functions which can be easily used by including <algorithm> header. Some of the algorithms are –

- - - - Sort
        
        Merge
        
        Min
        
        Max
        
        Swap
        
        Replace
        
        Compare

And much more

Function Object

A function object is also known as a functor. A functor is any type that implements operator(). C++ STL mainly uses functors as sorting criteria for containers. Example –

struct Functor
{
    bool operator()(int a, int b)
    {
        return a < b;
    }
};

In the later tutorials, we will talk about every single of them in depth.

First we will start with containers, more specifically sequential containers and we will work our way up to STL algorithms.

🔑 Prerequisite skills for this tutorial series