Standard library header <deque>

C++

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Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

Standard Library header files

Language Support
<cstddef> <limits> <climits> <contract>	<cfloat> <cstdint> <new> <version>	<typeinfo> <exception> <initializer_list>	<csignal> <csetjmp> <cstdarg>
Concepts
<concepts>
Diagnostics
<stdexcept>	<cassert>	<cerrno>	<system_error>
General utilities
<utility> <memory> <memory_resource> <scoped_allocator> <compare>	<bitset> <tuple> <optional> <any> <variant>	<type_traits> <ratio> <chrono> <typeindex> <functional>	<ctime> <cstdlib>
Strings
<string> <string_view>	<cctype> <cwctype>	<cwchar> <cuchar>	<cstring> <charconv>
Localization
<locale>	<codecvt>	<clocale>
Containers
<span> <array> <vector>	<deque> <forward_list> <list>	<map> <set> <queue>	<unordered_map> <unordered_set> <stack>
Iterators
<iterator>
Algorithms
<algorithm>	<execution>
Numerics
<complex> <random>	<valarray> <numeric>	<cfenv> <cmath>	<bit>
Input/Output
<iosfwd> <ios> <iomanip> <streambuf>	<istream> <ostream> <iostream>	<sstream> <fstream> <syncstream>	<cstdio> <cinttypes> <strstream>
Regular expressions
<regex>
Filesystem support
<filesystem>
Thread support
<thread> <atomic>	<mutex> <shared_mutex>	<condition_variable> <future>
C compatibility
<ciso646> <cstdalign>	<cstdbool> <ccomplex>	<ctgmath>

This header is part of the containers library.

Classes
deque	double-ended queue (class template)
Functions
operator==operator!=operator<operator<=operator>operator>=	lexicographically compares the values in the deque (function template)
std::swap(std::deque)	specializes the std::swap algorithm (function template)

Synopsis

#include <initializer_list>

namespace std {
    template <class T, class Allocator = allocator<T> > class deque;

    template <class T, class Allocator>
        bool operator==(const deque<T,Allocator>& x, const deque<T,Allocator>& y);
    template <class T, class Allocator>
        bool operator<(const deque<T,Allocator>& x, const deque<T,Allocator>& y);
    template <class T, class Allocator>
        bool operator!=(const deque<T,Allocator>& x, const deque<T,Allocator>& y);
    template <class T, class Allocator>
        bool operator>(const deque<T,Allocator>& x, const deque<T,Allocator>& y);
    template <class T, class Allocator>
        bool operator>=(const deque<T,Allocator>& x, const deque<T,Allocator>& y);
    template <class T, class Allocator>
        bool operator<=(const deque<T,Allocator>& x, const deque<T,Allocator>& y);

    template <class T, class Allocator>
        void swap(deque<T,Allocator>& x, deque<T,Allocator>& y);
}

Class std::deque

template <class T, class Allocator = allocator<T> >
class deque {
public:
    // types:
    typedef value_type&                                         reference;
    typedef const value_type&                                   const_reference;
    typedef /*implementation-defined*/                          iterator;
    typedef /*implementation-defined*/                          const_iterator; 
    typedef /*implementation-defined*/                          size_type;
    typedef /*implementation-defined*/                          difference_type;
    typedef T                                                   value_type;
    typedef Allocator                                           allocator_type;
    typedef typename allocator_traits<Allocator>::pointer       pointer;
    typedef typename allocator_traits<Allocator>::const_pointer const_pointer;
    typedef std::reverse_iterator<iterator>                     reverse_iterator;
    typedef std::reverse_iterator<const_iterator>               const_reverse_iterator;

    // construct/copy/destroy:
    explicit deque(const Allocator& = Allocator());
    explicit deque(size_type n);
    deque(size_type n, const T& value,const Allocator& = Allocator());
    template <class InputIterator>
        deque(InputIterator first, InputIterator last,const Allocator& = Allocator());
    deque(const deque<T,Allocator>& x);
    deque(deque&&);
    deque(const deque&, const Allocator&);
    deque(deque&&, const Allocator&);
    deque(initializer_list<T>, const Allocator& = Allocator());

    ~deque();
    deque<T,Allocator>& operator=(const deque<T,Allocator>& x);
    deque<T,Allocator>& operator=(deque<T,Allocator>&& x);
    deque& operator=(initializer_list<T>);
    template <class InputIterator>
    void assign(InputIterator first, InputIterator last);
    void assign(size_type n, const T& t);
    void assign(initializer_list<T>);
    allocator_type get_allocator() const noexcept;

    // iterators:
    iterator                begin() noexcept;
    const_iterator          begin() const noexcept;
    iterator                end() noexcept;
    const_iterator          end() const noexcept;

    reverse_iterator        rbegin() noexcept;
    const_reverse_iterator  rbegin() const noexcept;
    reverse_iterator        rend() noexcept;
    const_reverse_iterator  rend() const noexcept;

    const_iterator          cbegin() noexcept;
    const_iterator          cend() noexcept;
    const_reverse_iterator  crbegin() const noexcept;
    const_reverse_iterator  crend() const noexcept;

    // capacity:
    size_type size() const noexcept;
    size_type max_size() const noexcept;
    void      resize(size_type sz);
    void      resize(size_type sz, const T& c);
    void      shrink_to_fit();
    bool      empty() const noexcept;

    // element access:
    reference       operator[](size_type n);
    const_reference operator[](size_type n) const;
    reference       at(size_type n);
    const_reference at(size_type n) const;
    reference       front();
    const_reference front() const;
    reference       back();
    const_reference back() const;

    // modifiers:
    template <class... Args> void emplace_front(Args&&... args);
    template <class... Args> void emplace_back(Args&&... args);
    template <class... Args> iterator emplace(const_iterator position, Args&&... args);

    void push_front(const T& x);
    void push_front(T&& x);
    void push_back(const T& x);
    void push_back(T&& x);

    iterator insert(const_iterator position, const T& x);
    iterator insert(const_iterator position, T&& x);
    iterator insert(const_iterator position, size_type n, const T& x);
    template <class InputIterator>
        iterator insert (const_iterator position, InputIterator first, 
                         InputIterator last);
    iterator insert(const_iterator position, initializer_list<T>);

    void pop_front();
    void pop_back();

    iterator erase(const_iterator position);
    iterator erase(const_iterator first, const_iterator last);
    void     swap(deque<T,Allocator>&);
    void     clear() noexcept;
};