std::deque::deque

 

C++

Language

Standard library headers

Concepts

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

 

Containers library

array (C++11)

vector

deque

forward_list (C++11)

list

set

multiset

map

multimap

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

stack

queue

priority_queue

 

std::deque

Member functions

deque::deque

deque::~deque

deque::operator=

deque::assign

deque::get_allocator

Element access

deque::front

deque::back

Iterators

deque::begindeque::cbegin (C++11)

deque::enddeque::cend (C++11)

deque::rbegindeque::crbegin (C++11)

deque::renddeque::crend (C++11)

Capacity

deque::empty

deque::size

deque::max_size

deque::shrink_to_fit

Modifiers

deque::clear

deque::insert

deque::emplace

deque::erase

deque::push_front

deque::emplace_front

deque::pop_front

deque::push_back

deque::emplace_back

deque::pop_back

deque::resize

deque::swap

 

	(1)
explicit deque( const Allocator& alloc = Allocator() );			(until C++14)
deque() : deque( Allocator() ) {} explicit deque( const Allocator& alloc );			(since C++14)
		(2)
explicit deque( size_type count,                 const T& value = T(),                 const Allocator& alloc = Allocator());				(until C++11)
deque( size_type count,                 const T& value,                 const Allocator& alloc = Allocator());				(since C++11)
			(3)
explicit deque( size_type count );					(since C++11) (until C++14)
explicit deque( size_type count, const Allocator& alloc = Allocator() );					(since C++14)
template< class InputIt > deque( InputIt first, InputIt last,        const Allocator& alloc = Allocator() );				(4)
deque( const deque& other );				(5)
deque( const deque& other, const Allocator& alloc );				(5)	(since C++11)
deque( deque&& other )				(6)	(since C++11)
deque( deque&& other, const Allocator& alloc );				(6)	(since C++11)
deque( std::initializer_list<T> init,        const Allocator& alloc = Allocator() );				(7)	(since C++11)

Constructs a new container from a variety of data sources, optionally using a user supplied allocator alloc.

1) Default constructor. Constructs an empty container.

2) Constructs the container with count copies of elements with value value.

3) Constructs the container with count default-inserted instances of T. No copies are made.

4) Constructs the container with the contents of the range [first, last).

This constructor has the same effect as overload (2) if InputIt is an integral type.	(until C++11)
This overload only participates in overload resolution if InputIt satisfies InputIterator , to avoid ambiguity with the overload (2).	(since C++11)

5) Copy constructor. Constructs the container with the copy of the contents of other. If alloc is not provided, allocator is obtained by calling std::allocator_traits<allocator_type>::select_on_container_copy_construction(other.get_allocator().

6) Move constructor. Constructs the container with the contents of other using move semantics. If alloc is not provided, allocator is obtained by move-construction from the allocator belonging to other.

7) Constructs the container with the contents of the initializer list init.

Parameters

alloc	-	allocator to use for all memory allocations of this container
count	-	the size of the container
value	-	the value to initialize elements of the container with
first, last	-	the range to copy the elements from
other	-	another container to be used as source to initialize the elements of the container with
init	-	initializer list to initialize the elements of the container with

Complexity

1) Constant

2-3) Linear in count

4) Linear in distance between first and last

5) Linear in size of other

6) Constant. If alloc is given and alloc != other.get_allocator(), then linear.

7) Linear in size of init

Example

Run this code

#include <deque>
#include <string>
#include <iostream>
 
template<typename T>
std::ostream& operator<<(std::ostream& s, const std::deque<T>& v) {
    s.put('[');
    char comma[3] = {'\0', ' ', '\0'};
    for (const auto& e : v) {
        s << comma << e;
        comma[0] = ',';
    }
    return s << ']';
}
 
int main() 
{
    // c++11 initializer list syntax:
    std::deque<std::string> words1 {"the", "frogurt", "is", "also", "cursed"};
    std::cout << "words1: " << words1 << '\n';
 
    // words2 == words1
    std::deque<std::string> words2(words1.begin(), words1.end());
    std::cout << "words2: " << words2 << '\n';
 
    // words3 == words1
    std::deque<std::string> words3(words1);
    std::cout << "words3: " << words3 << '\n';
 
    // words4 is {"Mo", "Mo", "Mo", "Mo", "Mo"}
    std::deque<std::string> words4(5, "Mo");
    std::cout << "words4: " << words4 << '\n';
}

Output:

words1: [the, frogurt, is, also, cursed]
words2: [the, frogurt, is, also, cursed]
words3: [the, frogurt, is, also, cursed]
words4: [Mo, Mo, Mo, Mo, Mo]

See also

assign	assigns values to the container (public member function)
operator=	assigns values to the container (public member function)