std::list (3) - Linux Manuals

std::list: std::list

NAME

std::list - std::list

Synopsis

Defined in header <list>
template<
class T, (1)
class Allocator = std::allocator<T>
> class list;
namespace pmr {
template <class T> (2) (since C++17)
using list = std::list<T, std::pmr::polymorphic_allocator<T>>;
}

std::list is a container that supports constant time insertion and removal of elements from anywhere in the container. Fast random access is not supported. It is usually implemented as a doubly-linked list. Compared to std::forward_list this container provides bidirectional iteration capability while being less space efficient.
Adding, removing and moving the elements within the list or across several lists does not invalidate the iterators or references. An iterator is invalidated only when the corresponding element is deleted.
std::list meets the requirements of Container, AllocatorAwareContainer, SequenceContainer and ReversibleContainer.

Template parameters

            The type of the elements.

            T must meet the requirements of CopyAssignable and CopyConstructible. (until C++11)
T - The requirements that are imposed on the elements depend on the actual operations performed on the container. Generally, it is required that element type is a complete type and meets the requirements of Erasable, but many member functions impose stricter requirements. (since C++11)
                                                                                                                                                                                                                                                                                                                                                                                                                               (until C++17)
            The requirements that are imposed on the elements depend on the actual operations performed on the container. Generally, it is required that element type meets the requirements of Erasable, but many member functions impose stricter requirements. This container (but not its members) can be instantiated with an incomplete element type if the allocator satisfies the allocator_completeness_requirements. (since C++17)

Allocator - An allocator that is used to acquire/release memory and to construct/destroy the elements in that memory. The type must meet the requirements of Allocator. The behavior is undefined if Allocator::value_type is not the same as T.

Member types

Member type Definition
value_type T
allocator_type Allocator
size_type Unsigned integer type (usually std::size_t)
difference_type Signed integer type (usually std::ptrdiff_t)

reference Allocator::reference (until C++11)
                       value_type& (since C++11)

const_reference Allocator::const_reference (until C++11)
                       const value_type& (since C++11)

pointer Allocator::pointer (until C++11)
                       std::allocator_traits<Allocator>::pointer (since C++11)

const_pointer Allocator::const_pointer (until C++11)
                       std::allocator_traits<Allocator>::const_pointer (since C++11)

iterator LegacyBidirectionalIterator
const_iterator Constant LegacyBidirectionalIterator
reverse_iterator std::reverse_iterator<iterator>
const_reverse_iterator std::reverse_iterator<const_iterator>

Member functions

              constructs the list
constructor (public member function)
              destructs the list
destructor (public member function)
              assigns values to the container
operator= (public member function)
              assigns values to the container
assign (public member function)
              returns the associated allocator
get_allocator (public member function)

Element access

              access the first element
front (public member function)
              access the last element
back (public member function)

Iterators

begin returns an iterator to the beginning
cbegin (public member function)

end_ returns an iterator to the end
cend (public member function)

rbegin returns a reverse iterator to the beginning
crbegin (public member function)

rend returns a reverse iterator to the end
crend (public member function)

Capacity

              checks whether the container is empty
empty (public member function)
              returns the number of elements
size (public member function)
              returns the maximum possible number of elements
max_size (public member function)

Modifiers

              clears the contents
clear (public member function)
              inserts elements
insert (public member function)

emplace constructs element in-place
              (public member function)
(C++11)
              erases elements
erase (public member function)
              adds an element to the end
push_back (public member function)

emplace_back constructs an element in-place at the end
              (public member function)
(C++11)
              removes the last element
pop_back (public member function)
              inserts an element to the beginning
push_front (public member function)

emplace_front constructs an element in-place at the beginning
              (public member function)
(C++11)
              removes the first element
pop_front (public member function)
              changes the number of elements stored
resize (public member function)
              swaps the contents
swap (public member function)

Operations

              merges two sorted lists
merge (public member function)
              moves elements from another list
splice (public member function)
              removes elements satisfying specific criteria
remove (public member function)
remove_if
              reverses the order of the elements
reverse (public member function)
              removes consecutive duplicate elements
unique (public member function)
              sorts the elements
sort (public member function)

Non-member functions

operator==
operator!= lexicographically compares the values in the list
operator< (function template)
operator<=
operator>
operator>=
                     specializes the std::swap algorithm
std::swap(std::list) (function template)

erase(std::list) Erases all elements satisfying specific criteria
erase_if(std::list) (function template)

(C++20)

Deduction_guides(since C++17)

Example

// Run this code

  #include <algorithm>
  #include <iostream>
  #include <list>

  int main()
  {
      // Create a list containing integers
      std::list<int> l = { 7, 5, 16, 8 };

      // Add an integer to the front of the list
      l.push_front(25);
      // Add an integer to the back of the list
      l.push_back(13);

      // Insert an integer before 16 by searching
      auto it = std::find(l.begin(), l.end(), 16);
      if (it != l.end()) {
          l.insert(it, 42);
      }

      // Iterate and print values of the list
      for (int n : l) {
          std::cout << n << '\n';
      }
  }

Output:

  25
  7
  5
  42
  16
  8
  13