<list>

Include the STL standard header <list> to define the container template class list and several supporting templates.

namespace std {
template<class Ty, class Alloc>
    class list;

        // TEMPLATE FUNCTIONS
template<class Ty, class Alloc>
    bool operator==(
        const list<Ty, Alloc>& left,
        const list<Ty, Alloc>& right);
template<class Ty, class Alloc>
    bool operator!=(
        const list<Ty, Alloc>& left,
        const list<Ty, Alloc>& right);
template<class Ty, class Alloc>
    bool operator<(
        const list<Ty, Alloc>& left,
        const list<Ty, Alloc>& right);
template<class Ty, class Alloc>
    bool operator>(
        const list<Ty, Alloc>& left,
        const list<Ty, Alloc>& right);
template<class Ty, class Alloc>
    bool operator<=(
        const list<Ty, Alloc>& left,
        const list<Ty, Alloc>& right);
template<class Ty, class Alloc>
    bool operator>=(
        const list<Ty, Alloc>& left,
        const list<Ty, Alloc>& right);
template<class Ty, class Alloc>
    void swap(
        list<Ty, Alloc>& left,
        list<Ty, Alloc>& right);
    };

list

allocator_type · assign · back · begin · clear · const_iterator · const_pointer · const_reference · const_reverse_iterator · difference_type · empty · end · erase · front · get_allocator · insert · iterator · list · max_size · merge · pointer · pop_back · pop_front · push_back · push_front · rbegin · reference · remove · remove_if · rend · resize · reverse · reverse_iterator · size · size_type · sort · splice · swap · unique · value_type

template<class Ty, class Alloc = allocator<Ty> >
    class list {
public:
    typedef Alloc allocator_type;
    typedef typename Alloc::pointer pointer;
    typedef typename Alloc::const_pointer
        const_pointer;
    typedef typename Alloc::reference reference;
    typedef typename Alloc::const_reference const_reference;
    typedef typename Alloc::value_type value_type;
    typedef T0 iterator;
    typedef T1 const_iterator;
    typedef T2 size_type;
    typedef T3 difference_type;
    typedef reverse_iterator<const_iterator>
        const_reverse_iterator;
    typedef reverse_iterator<iterator>
        reverse_iterator;
    list();
    explicit list(const Alloc& al);
    explicit list(size_type count);
    list(size_type count, const Ty& val);
    list(size_type count, const Ty& val, const Alloc& al);
    list(const list& right);
    template<class InIt>
        list(InIt first, InIt last);
    template<class InIt>
        list(InIt first, InIt last, const Alloc& al);
    iterator begin();
    const_iterator begin() const;
    iterator end();
    const_iterator end() const;
    reverse_iterator rbegin();
    const_reverse_iterator rbegin() const;
    reverse_iterator rend();
    const_reverse_iterator rend() const;
    void resize(size_type newsize);
    void resize(size_type newsize, Ty val);
    size_type size() const;
    size_type max_size() const;
    bool empty() const;
    Alloc get_allocator() const;
    reference front();
    const_reference front() const;
    reference back();
    const_reference back() const;
    void push_front(const Ty& val);
    void pop_front();
    void push_back(const Ty& val);
    void pop_back();
    template<class InIt>
        void assign(InIt first, InIt last);
    void assign(size_type count, const Ty& val);
    iterator insert(iterator where, const Ty& val);
    void insert(iterator where, size_type count, const Ty& val);
    template<class InIt>
        void insert(iterator where, InIt first, InIt last);
    iterator erase(iterator where);
    iterator erase(iterator first, iterator last);
    void clear();
    void swap(list& right);
    void splice(iterator where, list& right);
    void splice(iterator where, list& right, iterator first);
    void splice(iterator where, list& right, iterator first,
        iterator last);
    void remove(const Ty& val);
    templace<class Pr1>
        void remove_if(Pr1 pred);
    void unique();
    template<class Pr2>
        void unique(Pr2 pred);
    void merge(list& right);
    template<class Pr3>
        void merge(list& right, Pr3 pred);
    void sort();
    template<class Pr3>
        void sort(Pr3 pred);
    void reverse();
    };

The template class describes an object that controls a varying-length sequence of elements of type Ty. The sequence is stored as a bidirectional linked list of elements, each containing a member of type Ty.

The object allocates and frees storage for the sequence it controls through a stored allocator object of class Alloc. Such an allocator object must have the same external interface as an object of template class allocator. Note that the stored allocator object is not copied when the container object is assigned.

List reallocation occurs when a member function must insert, erase, or splice elements of the controlled sequence. In all such cases, only iterators or references that designate erased or spliced elemets of the controlled sequence become invalid.

All additions to the controlled sequence occur as if by calls to insert, which is the only member function that calls the constructor Ty(const Ty&). If such an expression throws an exception, the container object inserts no new elements and rethrows the exception. Thus, an object of template class list is left in a known state when such exceptions occur.

list::allocator_type

typedef Alloc allocator_type;

The type is a synonym for the template parameter Alloc.

list::assign

template<class InIt>
    void assign(InIt first, InIt last);
void assign(size_type count, const Ty& val);

If InIt is an integer type, the first member function behaves the same as assign((size_type)first, (Ty)last). Otherwise, the first member function replaces the sequence controlled by *this with the sequence [first, last), which must not overlap the initial controlled sequence. The second member function replaces the sequence controlled by *this with a repetition of count elements of value val.

list::back

reference back();
const_reference back() const;

The member function returns a reference to the last element of the controlled sequence, which must be non-empty.

list::begin

const_iterator begin() const;
iterator begin();

The member function returns a bidirectional iterator that points at the first element of the sequence (or just beyond the end of an empty sequence).

list::clear

void clear();

The member function calls erase( begin(), end()).

list::const_iterator

typedef T1 const_iterator;

The type describes an object that can serve as a constant bidirectional iterator for the controlled sequence. It is described here as a synonym for the implementation-defined type T1.

list::const_pointer

typedef typename Alloc::const_pointer
    const_pointer;

The type describes an object that can serve as a constant pointer to an element of the controlled sequence.

list::const_reference

typedef typename Alloc::const_reference const_reference;

The type describes an object that can serve as a constant reference to an element of the controlled sequence.

list::const_reverse_iterator

typedef reverse_iterator<const_iterator>
    const_reverse_iterator;

The type describes an object that can serve as a constant reverse bidirectional iterator for the controlled sequence.

list::difference_type

typedef T3 difference_type;

The signed integer type describes an object that can represent the difference between the addresses of any two elements in the controlled sequence. It is described here as a synonym for the implementation-defined type T3.

list::empty

bool empty() const;

The member function returns true for an empty controlled sequence.

list::end

const_iterator end() const;
iterator end();

The member function returns a bidirectional iterator that points just beyond the end of the sequence.

list::erase

iterator erase(iterator where);
iterator erase(iterator first, iterator last);

The first member function removes the element of the controlled sequence pointed to by where. The second member function removes the elements of the controlled sequence in the range [first, last). Both return an iterator that designates the first element remaining beyond any elements removed, or end() if no such element exists.

Erasing N elements causes N destructor calls. Reallocation occurs, so iterators and references become invalid for the erased elements.

The member functions never throw an exception.

list::front

reference front();
const_reference front() const;

The member function returns a reference to the first element of the controlled sequence, which must be non-empty.

list::get_allocator

Alloc get_allocator() const;

The member function returns the stored allocator object.

list::insert

iterator insert(iterator where, const Ty& val);
void insert(iterator where, size_type count, const Ty& val);
template<class InIt>
    void insert(iterator where, InIt first, InIt last);

Each of the member functions inserts, before the element pointed to by where in the controlled sequence, a sequence specified by the remaining operands. The first member function inserts a single element with value val and returns an iterator that designates the newly inserted element. The second member function inserts a repetition of count elements of value val.

If InIt is an integer type, the last member function behaves the same as insert(where, (size_type)first, (Ty)last). Otherwise, the last member function inserts the sequence [first, last), which must not overlap the initial controlled sequence.

Inserting N elements causes N constructor calls. Reallocation occurs, but no iterators or references become invalid.

If an exception is thrown during the insertion of one or more elements, the container is left unaltered and the exception is rethrown.

list::iterator

typedef T0 iterator;

The type describes an object that can serve as a bidirectional iterator for the controlled sequence. It is described here as a synonym for the implementation-defined type T0.

list::list

list();
explicit list(const Alloc& al);
explicit list(size_type count);
list(size_type count, const Ty& val);
list(size_type count, const Ty& val,
    const Alloc& al);
list(const list& right);
template<class InIt>
    list(InIt first, InIt last);
template<class InIt>
    list(InIt first, InIt last, const Alloc& al);

All constructors store an allocator object and initialize the controlled sequence. The allocator object is the argument al, if present. For the copy constructor, it is right.get_allocator(). Otherwise, it is Alloc().

The first two constructors specify an empty initial controlled sequence. The third constructor specifies a repetition of count elements of value Ty(). The fourth and fifth constructors specify a repetition of count elements of value val. The sixth constructor specifies a copy of the sequence controlled by right. If InIt is an integer type, the last two constructors specify a repetition of (size_type)first elements of value (Ty)last. Otherwise, the last two constructors specify the sequence [first, last).

list::max_size

size_type max_size() const;

The member function returns the length of the longest sequence that the object can control.

list::merge

void merge(list& right);
template<class Pr3>
    void merge(list& right, Pre3 pred);

Both member functions remove all elements from the sequence controlled by right and insert them in the controlled sequence. Both sequences must be ordered by the same predicate, described below. The resulting sequence is also ordered by that predicate.

For the iterators Pi and Pj designating elements at positions I and J, the first member function imposes the order !(*Pj < *Pi) whenever I < J. (The elements are sorted in ascending order.) The second member function imposes the order !pred(*Pj, *Pi) whenever I < J.

No pairs of elements in the original controlled sequence are reversed in the resulting controlled sequence. If a pair of elements in the resulting controlled sequence has equivalent ordering (!(*Pi < *Pj) && !(*Pj < *Pi)), an element from the original controlled sequence appears before an element from the sequence controlled by right.

An exception occurs only if pred throws an exception. In that case, the controlled sequence is left in unspecified order and the exception is rethrown.

list::pointer

typedef typename Alloc::pointer pointer;

The type describes an object that can serve as a pointer to an element of the controlled sequence.

list::pop_back

void pop_back();

The member function removes the last element of the controlled sequence, which must be non-empty.

The member function never throws an exception.

list::pop_front

void pop_front();

The member function removes the first element of the controlled sequence, which must be non-empty.

The member function never throws an exception.

list::push_back

void push_back(const Ty& val);

The member function inserts an element with value val at the end of the controlled sequence.

If an exception is thrown, the container is left unaltered and the exception is rethrown.

list::push_front

void push_front(const Ty& val);

The member function inserts an element with value val at the beginning of the controlled sequence.

If an exception is thrown, the container is left unaltered and the exception is rethrown.

list::rbegin

const_reverse_iterator rbegin() const;
reverse_iterator rbegin();

The member function returns a reverse bidirectional iterator that points just beyond the end of the controlled sequence. Hence, it designates the beginning of the reverse sequence.

list::reference

typedef typename Alloc::reference reference;

The type describes an object that can serve as a reference to an element of the controlled sequence.

list::remove

void remove(const Ty& val);

The member function removes from the controlled sequence all elements, designated by the iterator where, for which *where == val.

The member function never throws an exception.

list::remove_if

templace<class Pr1>
    void remove_if(Pr1 pred);

The member function removes from the controlled sequence all elements, designated by the iterator where, for which pred(*where) is true.

An exception occurs only if pred throws an exception. In that case, the controlled sequence is left in an unspecified state and the exception is rethrown.

list::rend

const_reverse_iterator rend() const;
reverse_iterator rend();

The member function returns a reverse bidirectional iterator that points at the first element of the sequence (or just beyond the end of an empty sequence). Hence, it designates the end of the reverse sequence.

list::resize

void resize(size_type newsize);
void resize(size_type newsize, Ty val);

The member functions both ensure that size() henceforth returns newsize. If it must make the controlled sequence longer, the first member function appends elements with value Ty(), while the second member function appends elements with value val. To make the controlled sequence shorter, both member functions call erase(begin() + newsize, end()).

list::reverse

void reverse();

The member function reverses the order in which elements appear in the controlled sequence.

list::reverse_iterator

typedef reverse_iterator<iterator>
    reverse_iterator;

The type describes an object that can serve as a reverse bidirectional iterator for the controlled sequence.

list::size

size_type size() const;

The member function returns the length of the controlled sequence.

list::size_type

typedef T2 size_type;

The unsigned integer type describes an object that can represent the length of any controlled sequence. It is described here as a synonym for the implementation-defined type T2.

list::sort

void sort();
template<class Pr3>
    void sort(Pr3 pred);

Both member functions order the elements in the controlled sequence by a predicate, described below.

For the iterators Pi and Pj designating elements at positions I and J, the first member function imposes the order !(*Pj < *Pi) whenever I < J. (The elements are sorted in ascending order.) The member template function imposes the order !pred(*Pj, *Pi) whenever I < J. No ordered pairs of elements in the original controlled sequence are reversed in the resulting controlled sequence. (The sort is stable.)

An exception occurs only if pred throws an exception. In that case, the controlled sequence is left in unspecified order and the exception is rethrown.

list::splice

void splice(iterator where, list& right);
void splice(iterator where, list& right, iterator first);
void splice(iterator where, list& right, iterator first,
    iterator last);

The first member function inserts the sequence controlled by right before the element in the controlled sequence pointed to by where. It also removes all elements from right. (&right must not equal this.)

The second member function removes the element pointed to by first in the sequence controlled by right and inserts it before the element in the controlled sequence pointed to by where. (If where == first || where == ++first, no change occurs.)

The third member function inserts the subrange designated by [first, last) from the sequence controlled by right before the element in the controlled sequence pointed to by where. It also removes the original subrange from the sequence controlled by right. (If &right == this, the range [first, last) must not include the element pointed to by where.)

If the third member function inserts N elements, and &right != this, an object of class iterator is incremented N times. For all splice member functions, If get_allocator() == str.get_allocator(), no exception occurs. Otherwise, a copy and a destructor call also occur for each inserted element.

Only iterators or references that designate spliced elements become invalid.

list::swap

void swap(list& right);

The member function swaps the controlled sequences between *this and where. If get_allocator() == where.get_allocator(), it does so in constant time, it throws no exceptions, and it invalidates no references, pointers, or iterators that designate elements in the two controlled sequences. Otherwise, it performs a number of element assignments and constructor calls proportional to the number of elements in the two controlled sequences.

list::unique

void unique();
template<class Pr2>
    void unique(Pr2 pred);

The first member function removes from the controlled sequence every element that compares equal to its preceding element. For the iterators Pi and Pj designating elements at positions I and J, the second member function removes every element for which I + 1 == J && pred(*Pi, *Pj).

For a controlled sequence of length N (> 0), the predicate pred(*Pi, *Pj) is evaluated N - 1 times.

An exception occurs only if pred throws an exception. In that case, the controlled sequence is left in an unspecified state and the exception is rethrown.

list::value_type

typedef typename Alloc::value_type value_type;

The type is a synonym for the template parameter Ty.

operator!=

template<class Ty, class Alloc>
    bool operator!=(
        const list <Ty, Alloc>& left,
        const list <Ty, Alloc>& right);

The template function returns !(left == right).

operator==

template<class Ty, class Alloc>
    bool operator==(
        const list <Ty, Alloc>& left,
        const list <Ty, Alloc>& right);

The template function overloads operator== to compare two objects of template class list. The function returns left.size() == right.size() && equal(left. begin(), left. end(), right.begin()).

operator<

template<class Ty, class Alloc>
    bool operator<(
        const list <Ty, Alloc>& left,
        const list <Ty, Alloc>& right);

The template function overloads operator< to compare two objects of template class list. The function returns lexicographical_compare(left. begin(), left. end(), right.begin(), right.end()).

operator<=

template<class Ty, class Alloc>
    bool operator<=(
        const list <Ty, Alloc>& left,
        const list <Ty, Alloc>& right);

The template function returns !(right < left).

operator>

template<class Ty, class Alloc>
    bool operator>(
        const list <Ty, Alloc>& left,
        const list <Ty, Alloc>& right);

The template function returns right < left.

operator>=

template<class Ty, class Alloc>
    bool operator>=(
        const list <Ty, Alloc>& left,
        const list <Ty, Alloc>& right);

The template function returns !(left < right).

swap

template<class Ty, class Alloc>
    void swap(
        list <Ty, Alloc>& left,
        list <Ty, Alloc>& right);

The template function executes left.swap(right).

See also the Table of Contents and the Index.

Copyright © 1994-2002 by P.J. Plauger. Portions derived from work copyright © 1994 by Hewlett-Packard Company. All rights reserved.