std::list(3)

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 CopyConstructible. T must meet the (until
               requirements of CopyAssignable if list::operator= or list::assign C++11)
               is instantiated with T.
               The requirements that are imposed on the elements depend on the (since
               actual operations performed on the container. Generally, it is C++11)
               required that element type is a complete type and meets the (until
               requirements of Erasable, but many member functions impose C++17)
               stricter requirements.
               The requirements that are imposed on the elements depend on the
               actual operations performed on the container. Generally, it is
   T - 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 (since
               requirements. C++17)
                        Feature-test macro Value Std Feature
                        Minimal
               __cpp_lib_incomplete_container_elements 201505L (C++17) incomplete
                        type
                        support
               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.
   Allocator - The behavior is undefined
               (until C++20)
               The program is ill-formed
               (since C++20) 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 value_type&
   const_reference const value_type&
                        Allocator::pointer (until C++11)
   pointer std::allocator_traits<Allocator>::pointer (since C++11)
                        Allocator::const_pointer (until C++11)
   const_pointer std::allocator_traits<Allocator>::const_pointer (since C++11)
   iterator LegacyBidirectionalIterator to value_type
   const_iterator LegacyBidirectionalIterator to const value_type
   reverse_iterator std::reverse_iterator<iterator>
   const_reverse_iterator std::reverse_iterator<const_iterator>

Member functions
   constructor constructs the list
                 (public member function)
   destructor destructs the list
                 (public member function)
   operator= assigns values to the container
                 (public member function)
   assign assigns values to the container
                 (public member function)
   assign_range assigns a range of values to the container
   (C++23) (public member function)
   get_allocator returns the associated allocator
                 (public member function)

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

Iterators
   begin returns an iterator to the beginning
   cbegin (public member function)
   (C++11)
   end returns an iterator to the end
   cend (public member function)
   (C++11)
   rbegin returns a reverse iterator to the beginning
   crbegin (public member function)
   (C++11)
   rend returns a reverse iterator to the end
   crend (public member function)
   (C++11)

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

Modifiers
   clear clears the contents
                 (public member function)
   insert inserts elements
                 (public member function)
   insert_range inserts a range of elements
   (C++23) (public member function)
   emplace constructs element in-place
   (C++11) (public member function)
   erase erases elements
                 (public member function)
   push_back adds an element to the end
                 (public member function)
   emplace_back constructs an element in-place at the end
   (C++11) (public member function)
   append_range adds a range of elements to the end
   (C++23) (public member function)
   pop_back removes the last element
                 (public member function)
   push_front inserts an element to the beginning
                 (public member function)
   emplace_front constructs an element in-place at the beginning
   (C++11) (public member function)
   prepend_range adds a range of elements to the beginning
   (C++23) (public member function)
   pop_front removes the first element
                 (public member function)
   resize changes the number of elements stored
                 (public member function)
   swap swaps the contents
                 (public member function)

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

Non-member functions
   operator==
   operator!=
   operator<
   operator<=
   operator>
   operator>= lexicographically compares the values of two lists
   operator<=> (function template)
   (removed in C++20)
   (removed in C++20)
   (removed in C++20)
   (removed in C++20)
   (removed in C++20)
   (C++20)
   std::swap(std::list) specializes the std::swap algorithm
                        (function template)
   erase(std::list) erases all elements satisfying specific criteria
   erase_if(std::list) (function template)
   (C++20)
     Deduction guides (since C++17)

Notes
       Feature-test macro Value Std Feature
   __cpp_lib_containers_ranges 202202L (C++23) Ranges construction and insertion for
                        containers

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);
     // Print out the list
     std::cout << "l = { ";
     for (int n : l)
         std::cout << n << ", ";
     std::cout << "};\n";
 }

Output:
 l = { 25, 7, 5, 42, 16, 8, 13, };
   Defect reports
   The following behavior-changing defect reports were applied retroactively to
   previously published C++ standards.
     DR Applied to Behavior as published Correct behavior
                      T was not required to be
   LWG 230 C++98 CopyConstructible T is also required to
                      (an element of type T might not be be CopyConstructible
                      able to be constructed)
   LWG 276 C++98 T was always required to be only required if operator= or
                      CopyAssignable assign is instantiated with T