STL : Things to remember

STL Benifits:
1.Code Reuse
2.Efficiancy and Fast
3.Accurate and less buggy
4.Simple code and readable
5.Standardized and helps in writing new libraries

Sequence Containers:

• Vector
• List
• DeQueue
• Array
• Forward List

 Associative Containers:

• Set
• Multi-Set
• Map
• Multi-Map

 Unordered Containers:

Vector Or List? :
Use vector

• When you have insertions and deletions at the end
• Accessing elements is a frequent randomly
• Dynamically grows

Use List

• Insertions and deletions any where in the list is required.
• Random accessing is not a frequent activity.

Iterators:
Random Access Iterator
Bi-Directional Iterator
Forward Iterator
Input Iterator
Const Iterator


Things to Remember:

1.Code Bloat : Template functions occupies own space for different types(Increases the object code)

2. For latest compilers square<int>(5) and square(5) are same. Where for class templates you have to explicitly specify the type.

3. template<class T> and template<typename T> are same.

4.Vector is dynamic array and can grow dynamically(its allocated on heap).

5. In  STL, .end() points to one element after the last element.

6.Accessing a container using iterator is faster and proper approach than using the subscript.

7.Forward list has only forward iterator

8. Once created , then size of the array can not be changed.

9.Associative containers are implemented using binary tree.

10. Associative containers are always sorted.

11.Set and Map holds no duplicate keys, where Multi-Set and Multi-Map can hold duplicate key.s

12.Keys can not be modified in associative containers.

13. Functor : Class + Function
    Overloads () operator and can maintain the state.

14. DO NOT use auto_ptr with STL containers as it transfers ownership , where as STL needs the elements to be copiable.