STL C++

The Standard Template Libraries (STL's) are a set of C++ template classes to provide common programming data structures and functions such as doubly linked lists (list), paired arrays (map), expandable arrays (vector), large string storage and manipulation (rope), etc. The STL library is available from the  STL home page . This is also your best detailed reference for all of the STL class functions available.

Also see our C++ Templates tutorial

STL can be categorized into the following groupings:

• Container classes:
  • Sequences:
    • vector: (this tutorial) Dynamic array of variables, struct or objects. Insert data at the end. 
      (also see the YoLinux.com tutorial on using and STL list and boost ptr_list to manage pointers.)
    • deque: Array which supports insertion/removal of elements at beginning or end of array
    • list: (this tutorial) Linked list of variables, struct or objects. Insert/remove anywhere.
  • Associative Containers:
    • set (duplicate data not allowed in set), multiset (duplication allowed): Collection of ordered data in a balanced binary tree structure. Fast search.
    • map (unique keys), multimap (duplicate keys allowed): Associative key-value pair held in balanced binary tree structure.
  • Container adapters:
    • stack LIFO
    • queue FIFO
    • priority_queue returns element with highest priority.
  • String:
    • string: Character strings and manipulation
    • rope: String storage and manipulation
  • bitset: Contains a more intuitive method of storing and manipulating bits.
• Operations/Utilities:
  • iterator: (examples in this tutorial) STL class to represent position in an STL container. An iterator is declared to be associated with a single container class type.
  • algorithm: Routines to find, count, sort, search, ... elements in container classes
  • auto_ptr: Class to manage memory pointers and avoid memory leaks.

STL vector:

Constructor/Declaration:

Method/operator	Description
vector<T> v;	Vector declaration of data type "T".
vector<T> v(size_type n);	Declaration of vector containing type "T" and of size "n" (quantity).
vector<T> v(size_type n,const T& t);	Declaration of vector containing type "T", of size "n" (quantity) containing value "t". Declaration: vector(size_type n, const T& t)
vector<T> v(begin_iterator,end_iterator);	Copy of Vector of data type "T" and range begin_iterator to end_iterator. Declaration: template vector(InputIterator, InputIterator)

Size methods/operators:

Method/operator	Description
empty()	Returns bool (true/false). True if empty. Declaration: bool empty() const
size()	Number of elements of vector. Declaration: size_type size() const
resize(n, t=T())	Adjust by adding or deleting elements of vector so that its size is "n". Declaration: void resize(n, t = T())
capacity()	Max number of elements of vector before reallocation. Declaration: size_type capacity() const
reserve(size_t n)	Max number of elements of vector set to "n" before reallocation. Declaration: void reserve(size_t)
max_size()	Max number of elements of vector possible. Declaration: size_type max_size() const

Note:  size_type is an unsigned integer.

Other methods/operators:

Method/operator	Description
erase() clear()	Erase all elements of vector. Declaration: void clear()
erase(iterator) erase(begin_iterator,end_iterator)	Erase element of vector. Returns iterator to next element. Erase element range of vector. Returns iterator to next element. Declarations: iterator erase(iterator pos) iterator erase(iterator first, iterator last)
= Example: X=Y()	Assign/copy entire contents of one vector into another. Declaration: vector& operator=(const vector&)
<	Comparison of one vector to another. Declaration: bool operator<(const vector&, const vector&)
==	Returns bool. True if every element is equal. Declaration: bool operator==(const vector&, const vector&)
at(index) v[index]	Element of vector. Left and Right value assignment: v.at(i)=e; and e=v.at(i); Declaration: reference operator[](size_type n)
front() v[0]	First element of vector. (Left and Right value assignment.) Declaration: reference front()
back()	Last element of vector. (Left and Right value assignment.) Declaration: reference back()
push_back(const T& value)	Add element to end of vector. Declaration: void push_back(const T&)
pop_back()	Remove element from end of vector. Declaration: void pop_back()
assign(size_type n,const T& t)	Assign first n elements a value "t".
assign(begin_iterator,end_iterator)	Replace data in range defined by iterators. Declaration:
insert(iterator, const T& t)	Insert at element "iterator", element of value "t". Declaration: iterator insert(iterator pos, const T& x)
insert(iterator pos, size_type n, const T& x)	Starting before element "pos", insert first n elements of value "x". Declaration: void insert(iterator pos, size_type n, const T& x)
insert(iterator pos, begin_iterator,end_iterator)	Starting before element "pos", insert range begin_iterator to end_iterator. Declaration: void insert(iterator pos, InputIterator f, InputIterator l)
swap(vector& v2)	Swap contents of two vectors. Declaration: void swap(vector&)

Iterator methods/operators:

Method/operator	Description
begin()	Return iterator to first element of vector. Declaration: const_iterator begin() const
end()	Return iterator to end of vector (not last element of vector but past last element) Declaration: const_iterator end() const
rbegin()	Return iterator to first element of vector (reverse order). Declaration: const_reverse_iterator rbegin() const
rend()	Return iterator to end of vector (not last element but past last element) (reverse order). Declaration: const_reverse_iterator rend() const
++	Increment iterator.
--	Decrement iterator.

STL list: