Standard library header <queue>

 

C++

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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)

Technical Specifications

 

Standard Library header files

Language Support
<cstddef> <limits> <climits> <cfloat> <cstdint> <new> <typeinfo> <exception> <ciso646>	<initializer_list> <csignal> <csetjmp> <cstdalign> <cstdarg> <cstdbool> <cstdlib> <ctime>
Diagnostics
<stdexcept> <cassert>	<cerrno> <system_error>
General utilities
<utility> <tuple> <bitset> <memory> <cstdlib> <cstring> <functional>	<type_traits> <ratio> <chrono> <ctime> <scoped_allocator> <typeindex>
Strings
<string> <cctype> <cwctype> <cstring>	<cwchar> <cstdlib> <cuchar>
Localization
<locale> <codecvt> <clocale>

Containers
<array> <deque> <forward_list> <list> <vector>	<map> <set> <unordered_map> <unordered_set> <queue> <stack>
Iterators
<iterator>
Algorithms
<algorithm>	<cstdlib>
Numerics
<cfenv> <complex> <random> <valarray>	<numeric> <cmath> <ctgmath> <cstdlib>
Input/Output
<iosfwd> <iostream> <ios> <streambuf> <istream> <ostream>	<iomanip> <sstream> <fstream> <cstdio> <cinttypes>
Regular expressions
<regex>
Thread support
<thread> <mutex> <atomic>	<shared_mutex> <condition_variable> <future>

 

This header is part of the containers library.

Includes
<initializer_list>(C++11)
Classes
queue	adapts a container to provide queue (FIFO data structure) (class template)
priority_queue	adapts a container to provide priority queue (class template)
std::uses_allocator<std::queue> (C++11)	specializes the std::uses_allocator type trait (function template)
std::uses_allocator<std::priority_queue> (C++11)	specializes the std::uses_allocator type trait (function template)
Functions
operator==operator!=operator<operator<=operator>operator>=	lexicographically compares the values in the queue (function template)
std::swap(std::queue)	specializes the std::swap algorithm (function template)
std::swap(std::priority_queue)	specializes the std::swap algorithm (function template)

Synopsis

namespace std {
    template <class T, class Container = deque<T> > class queue;
 
    template <class T,
              class Container = vector<T>,
              class Compare = less<typename Container::value_type> >
    class priority_queue;
 
    template <class T, class Container>
        bool operator==(const queue<T, Container>& x,const queue<T, Container>& y);
    template <class T, class Container>
        bool operator!=(const queue<T, Container>& x,const queue<T, Container>& y);
 
    template <class T, class Container>
        bool operator< (const queue<T, Container>& x,const queue<T, Container>& y);
    template <class T, class Container>
        bool operator> (const queue<T, Container>& x,const queue<T, Container>& y);
    template <class T, class Container>
        bool operator>=(const queue<T, Container>& x,const queue<T, Container>& y);
    template <class T, class Container>
        bool operator<=(const queue<T, Container>& x,const queue<T, Container>& y);
 
    template <class T, class Container>
        void swap(queue<T, Container>& x, queue<T, Container>& y)
            noexcept(noexcept(x.swap(y)));
 
    template <class T, class Container, class Compare>
        void swap(priority_queue<T, Container, Compare>& x,
                  priority_queue<T, Container, Compare>& y)
        noexcept(noexcept(x.swap(y)));
 
    template <class T, class Container, class Alloc>
        struct uses_allocator<queue<T, Container>, Alloc>
            : uses_allocator<Container, Alloc>::type { };
 
}

Class std::queue

template <class T, class Container = deque<T> >
class queue {
 public:
    typedef typename Container::value_type value_type;
    typedef typename Container::reference reference;
    typedef typename Container::const_reference const_reference;
    typedef typename Container::size_type size_type;
    typedef Container container_type;
 protected:
    Container c;
 public:
    explicit queue(const Container&);
    explicit queue(Container&& = Container());
    template <class Alloc> explicit queue(const Alloc&);
    template <class Alloc> queue(const Container&, const Alloc&);
    template <class Alloc> queue(Container&&, const Alloc&);
    template <class Alloc> queue(const queue&, const Alloc&);
    template <class Alloc> queue(queue&&, const Alloc&);
 
    bool empty() const {
        return c.empty();
    }
    size_type size() const {
        return c.size();
    }
    reference front() {
        return c.front();
    }
    const_reference front() const {
        return c.front();
    }
    reference back() {
        return c.back();
    }
    const_reference back() const {
        return c.back();
    }
    void push(const value_type& x) {
        c.push_back(x);
    }
    void push(value_type&& x) {
        c.push_back(std::move(x));
    }
    template <class... Args> void emplace(Args&&... args) {
        c.emplace_back(std::forward<Args>(args)...);
    }
    void pop() {
        c.pop_front();
    }
    void swap(queue& q) noexcept(noexcept(swap(c, q.c))) {
        using std::swap;
        swap(c, q.c);
    }
};

Class std::priority_queue

template <class T,
          class Container = vector<T>,
          class Compare = less<typename Container::value_type> >
class priority_queue {
 public:
    typedef typename Container::value_type value_type;
    typedef typename Container::reference reference;
    typedef typename Container::const_reference const_reference;
    typedef typename Container::size_type size_type;
    typedef Container container_type;
 protected:
    Container c;
    Compare comp;
 public:
    priority_queue(const Compare& x, const Container&);
    explicit priority_queue(const Compare& x = Compare(), Container&& = Container());
    template <class InputIterator>
    priority_queue(InputIterator first, InputIterator last,
                       const Compare& x, const Container&);
    template <class InputIterator>
    priority_queue(InputIterator first, InputIterator last,
                   const Compare& x = Compare(), Container&& = Container());
    template <class Alloc> explicit priority_queue(const Alloc&);
    template <class Alloc> priority_queue(const Compare&, const Alloc&);
    template <class Alloc> priority_queue(const Compare&,
                                          const Container&, const Alloc&);
    template <class Alloc> priority_queue(const Compare&,
                                          Container&&, const Alloc&);
    template <class Alloc> priority_queue(const priority_queue&, const Alloc&);
    template <class Alloc> priority_queue(priority_queue&&, const Alloc&);
 
    bool empty() const {
        return c.empty();
    }
    size_type size() const {
        return c.size();
    }
    const_reference top() const {
        return c.front();
    }
    void push(const value_type& x);
    void push(value_type&& x);
    template <class... Args> void emplace(Args&&... args);
    void pop();
    void swap(priority_queue& q) noexcept( noexcept(swap(c, q.c))
                                        && noexcept(swap(comp, q.comp))) {
        using std::swap;
        swap(c, q.c);
        swap(comp, q.comp);
    }
};