C++

Reference

<list>

list

class template
<list>

std::list

template < class T, class Alloc = allocator<T> > class list;
List
Lists are sequence containers that allow constant time insert and erase operations anywhere within the sequence, and iteration in both directions.

List containers are implemented as doubly-linked lists; Doubly linked lists can store each of the elements they contain in different and unrelated storage locations. The ordering is kept internally by the association to each element of a link to the element preceding it and a link to the element following it.

They are very similar to forward_list: The main difference being that forward_list objects are single-linked lists, and thus they can only be iterated forwards, in exchange for being somewhat smaller and more efficient.

Compared to other base standard sequence containers (array, vector and deque), lists perform generally better in inserting, extracting and moving elements in any position within the container for which an iterator has already been obtained, and therefore also in algorithms that make intensive use of these, like sorting algorithms.

The main drawback of lists and forward_lists compared to these other sequence containers is that they lack direct access to the elements by their position; For example, to access the sixth element in a list, one has to iterate from a known position (like the beginning or the end) to that position, which takes linear time in the distance between these. They also consume some extra memory to keep the linking information associated to each element (which may be an important factor for large lists of small-sized elements).

Container properties

Sequence
Elements in sequence containers are ordered in a strict linear sequence. Individual elements are accessed by their position in this sequence.
Doubly-linked list
Each element keeps information on how to locate the next and the previous elements, allowing constant time insert and erase operations before or after a specific element (even of entire ranges), but no direct random access.
Allocator-aware
The container uses an allocator object to dynamically handle its storage needs.

Template parameters

T
Type of the elements.
Aliased as member type list::value_type.
Alloc
Type of the allocator object used to define the storage allocation model. By default, the allocator class template is used, which defines the simplest memory allocation model and is value-independent.
Aliased as member type list::allocator_type.

Member types

member typedefinitionnotes
value_typeThe first template parameter (T)
allocator_typeThe second template parameter (Alloc)defaults to: allocator<value_type>
referenceallocator_type::referencefor the default allocator: value_type&
const_referenceallocator_type::const_referencefor the default allocator: const value_type&
pointerallocator_type::pointerfor the default allocator: value_type*
const_pointerallocator_type::const_pointerfor the default allocator: const value_type*
iteratora bidirectional iterator to value_typeconvertible to const_iterator
const_iteratora bidirectional iterator to const value_type
reverse_iteratorreverse_iterator<iterator>
const_reverse_iteratorreverse_iterator<const_iterator>
difference_typea signed integral type, identical to: iterator_traits<iterator>::difference_typeusually the same as ptrdiff_t
size_typean unsigned integral type that can represent any non-negative value of difference_typeusually the same as size_t
member typedefinitionnotes
value_typeThe first template parameter (T)
allocator_typeThe second template parameter (Alloc)defaults to: allocator<value_type>
referencevalue_type&
const_referenceconst value_type&
pointerallocator_traits<allocator_type>::pointerfor the default allocator: value_type*
const_pointerallocator_traits<allocator_type>::const_pointerfor the default allocator: const value_type*
iteratora bidirectional iterator to value_typeconvertible to const_iterator
const_iteratora bidirectional iterator to const value_type
reverse_iteratorreverse_iterator<iterator>
const_reverse_iteratorreverse_iterator<const_iterator>
difference_typea signed integral type, identical to:
iterator_traits<iterator>::difference_type		usually the same as ptrdiff_t
size_typean unsigned integral type that can represent any non-negative value of difference_typeusually the same as size_t


Member functions

(constructor)
Construct list (public member function)
(destructor)
List destructor (public member function)
operator=
Assign content (public member function)

Iterators:
begin
Return iterator to beginning (public member function)
end
Return iterator to end (public member function)
rbegin
Return reverse iterator to reverse beginning (public member function)
rend
Return reverse iterator to reverse end (public member function)
cbegin
Return const_iterator to beginning (public member function)
cend
Return const_iterator to end (public member function)
crbegin
Return const_reverse_iterator to reverse beginning (public member function)
crend
Return const_reverse_iterator to reverse end (public member function)

Capacity:
empty
Test whether container is empty (public member function)
size
Return size (public member function)
max_size
Return maximum size (public member function)

Element access:
front
Access first element (public member function)
back
Access last element (public member function)

Modifiers:
assign
Assign new content to container (public member function)
emplace_front
Construct and insert element at beginning (public member function)
push_front
Insert element at beginning (public member function)
pop_front
Delete first element (public member function)
emplace_back
Construct and insert element at the end (public member function)
push_back
Add element at the end (public member function)
pop_back
Delete last element (public member function)
emplace
Construct and insert element (public member function)
insert
Insert elements (public member function)
erase
Erase elements (public member function)
swap
Swap content (public member function)
resize
Change size (public member function)
clear
Clear content (public member function)

Operations:
splice
Transfer elements from list to list (public member function)
remove
Remove elements with specific value (public member function)
remove_if
Remove elements fulfilling condition (public member function template)
unique
Remove duplicate values (public member function)
merge
Merge sorted lists (public member function)
sort
Sort elements in container (public member function)
reverse
Reverse the order of elements (public member function)

Observers:
get_allocator
Get allocator (public member function)

Non-member function overloads

relational operators (list)
Relational operators for list (function)
swap (list)
Exchanges the contents of two lists (function template)