Difference between revisions of "cpp/container/list"
From cppreference.com
m (→Example: made the output look alike the list itself.) |
(Added LWG issue #230 DR (part 3).) |
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===Template parameters=== | ===Template parameters=== | ||
{{par begin}} | {{par begin}} | ||
| − | {{par inc | cpp/container/param list T | list}} | + | {{par inc|cpp/container/param list T|list}} |
| − | {{par inc | cpp/container/param list Allocator | list}} | + | {{par inc|cpp/container/param list Allocator|list}} |
{{par end}} | {{par end}} | ||
| Line 104: | Line 104: | ||
{{example | {{example | ||
| − | + | | | |
| − | + | |code= | |
#include <algorithm> | #include <algorithm> | ||
#include <iostream> | #include <iostream> | ||
| Line 113: | Line 113: | ||
{ | { | ||
// Create a list containing integers | // Create a list containing integers | ||
| − | std::list<int> l = { 7, 5, 16, 8 }; | + | std::list<int> l = {7, 5, 16, 8}; |
| − | + | ||
// Add an integer to the front of the list | // Add an integer to the front of the list | ||
l.push_front(25); | l.push_front(25); | ||
// Add an integer to the back of the list | // Add an integer to the back of the list | ||
l.push_back(13); | l.push_back(13); | ||
| − | + | ||
// Insert an integer before 16 by searching | // Insert an integer before 16 by searching | ||
auto it = std::find(l.begin(), l.end(), 16); | auto it = std::find(l.begin(), l.end(), 16); | ||
| − | if (it != l.end()) | + | if (it != l.end()) |
l.insert(it, 42); | l.insert(it, 42); | ||
| − | + | ||
| − | + | ||
// Print out the list | // Print out the list | ||
std::cout << "l = { "; | std::cout << "l = { "; | ||
| − | for (int n : l) | + | for (int n : l) |
std::cout << n << ", "; | std::cout << n << ", "; | ||
| − | |||
std::cout << "};\n"; | std::cout << "};\n"; | ||
} | } | ||
| − | + | |output= | |
l = { 25, 7, 5, 42, 16, 8, 13, }; | l = { 25, 7, 5, 42, 16, 8, 13, }; | ||
}} | }} | ||
| + | |||
| + | ===Defect reports=== | ||
| + | {{dr list begin}} | ||
| + | {{dr list item|wg=lwg|dr=230|std=C++98|before={{tt|T}} was not required to be {{named req|CopyConstructible}}<br>(an element of type {{tt|T}} might not be able to be constructed)|after={{tt|T}} is also required to<br>be {{named req|CopyConstructible}}}} | ||
| + | {{dr list end}} | ||
{{langlinks|de|es|fr|it|ja|ko|pl|pt|ru|zh}} | {{langlinks|de|es|fr|it|ja|ko|pl|pt|ru|zh}} | ||
Revision as of 18:31, 11 October 2022
| Defined in header <list>
|
||
| template< class T, |
(1) | |
| namespace pmr { template <class T> |
(2) | (since C++17) |
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.
Contents |
Template parameters
| T | - | The type of the elements.
| ||||||||||||||
| 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(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& | ||||
pointer
|
| ||||
const_pointer
|
| ||||
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
constructs the list (public member function) | |
destructs the list (public member function) | |
| assigns values to the container (public member function) | |
| assigns values to the container (public member function) | |
| returns the associated allocator (public member function) | |
Element access | |
| access the first element (public member function) | |
| access the last element (public member function) | |
Iterators | |
| (C++11) |
returns an iterator to the beginning (public member function) |
| (C++11) |
returns an iterator to the end (public member function) |
| (C++11) |
returns a reverse iterator to the beginning (public member function) |
| (C++11) |
returns a reverse iterator to the end (public member function) |
Capacity | |
| checks whether the container is empty (public member function) | |
| returns the number of elements (public member function) | |
| returns the maximum possible number of elements (public member function) | |
Modifiers | |
| clears the contents (public member function) | |
| inserts elements (public member function) | |
| (C++11) |
constructs element in-place (public member function) |
| erases elements (public member function) | |
| adds an element to the end (public member function) | |
| (C++11) |
constructs an element in-place at the end (public member function) |
| removes the last element (public member function) | |
| inserts an element to the beginning (public member function) | |
| (C++11) |
constructs an element in-place at the beginning (public member function) |
| removes the first element (public member function) | |
| changes the number of elements stored (public member function) | |
| swaps the contents (public member function) | |
Operations | |
| merges two sorted lists (public member function) | |
moves elements from another list (public member function) | |
| removes elements satisfying specific criteria (public member function) | |
| reverses the order of the elements (public member function) | |
| removes consecutive duplicate elements (public member function) | |
| sorts the elements (public member function) | |
Non-member functions
| (removed in C++20)(removed in C++20)(removed in C++20)(removed in C++20)(removed in C++20)(C++20) |
lexicographically compares the values of two lists (function template) |
| specializes the std::swap algorithm (function template) | |
| erases all elements satisfying specific criteria (function template) |
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); // 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 |
|---|---|---|---|
| LWG 230 | C++98 | T was not required to be CopyConstructible(an element of type T might not be able to be constructed)
|
T is also required tobe CopyConstructible |
