deque::deque

Constructs a deque of a specific size, or with elements of a specific value, or with a specific allocator, or as a copy of all or part of some other deque.

deque( );
explicit deque(
    const Allocator& Al
);
explicit deque(
    size_type Count
);
deque(
    size_type Count,
    const Type& Val
);
deque(
    size_type Count,
    const Type& Val,
    const Allocator& Al
);
deque(
    const deque& Right
);
template<class InputIterator>
    deque(
        InputIterator First,
        InputIterator Last
    );
template<class InputIterator>
    deque(
        InputIterator First,
        InputIterator Last,
        const Allocator& Al
    );
deque(
    initializer_list<value_type> IList,
        const Allocator& Al
);

Parameters

Parameter

Description

Al

The allocator class to use with this object.

Count

The number of elements in the constructed deque.

Val

The value of the elements in the constructed deque.

Right

The deque of which the constructed deque is to be a copy.

First

Position of the first element in the range of elements to be copied.

Last

Position of the first element beyond the range of elements to be copied.

IList

The initializer_list to be copied.

Remarks

All constructors store an allocator object (Al) and initialize the deque.

The first two constructors specify an empty initial deque; the second one also specifies the allocator type (_Al) to be used.

The third constructor specifies a repetition of a specified number (_Count) of elements of the default value for class Type.

The fourth and fifth constructors specify a repetition of (Count) elements of value _Val.

The sixth constructor specifies a copy of the deque Right.

The seventh and eighth constructors copy the range [First, Last) of a deque.

The seventh constructor moves the deque Right.

The eighth constructor copies the contents of an initializer_list.

None of the constructors perform any interim reallocations.

Example

/ compile with: /EHsc
#include <deque>
#include <iostream>
#include <forward_list>

int main()
{
    using namespace std;

    forward_list<int> f1{ 1, 2, 3, 4 };

    f1.insert_after(f1.begin(), { 5, 6, 7, 8 });


    deque <int>::iterator c1_Iter, c2_Iter, c3_Iter, c4_Iter, c5_Iter, c6_Iter;

    // Create an empty deque c0
    deque <int> c0;

    // Create a deque c1 with 3 elements of default value 0
    deque <int> c1(3);

    // Create a deque c2 with 5 elements of value 2
    deque <int> c2(5, 2);

    // Create a deque c3 with 3 elements of value 1 and with the 
    // allocator of deque c2
    deque <int> c3(3, 1, c2.get_allocator());

    // Create a copy, deque c4, of deque c2
    deque <int> c4(c2);

    // Create a deque c5 by copying the range c4[_First, _Last)
    c4_Iter = c4.begin();
    c4_Iter++;
    c4_Iter++;
    deque <int> c5(c4.begin(), c4_Iter);

    // Create a deque c6 by copying the range c4[_First, _Last) and 
    // c2 with the allocator of deque
    c4_Iter = c4.begin();
    c4_Iter++;
    c4_Iter++;
    c4_Iter++;
    deque <int> c6(c4.begin(), c4_Iter, c2.get_allocator());

    // Create a deque c8 by copying the contents of an initializer_list
    // using brace initialization
    deque<int> c8({ 1, 2, 3, 4 });

    initializer_list<int> iList{ 5, 6, 7, 8 };
    deque<int> c9( iList);

    cout << "c1 = ";
    for (int i : c1)
        cout << i << " ";
    cout << endl;

    cout << "c2 = ";
    for (int i : c2)
        cout << i << " ";
    cout << endl;

    cout << "c3 = ";
    for (int i : c3)
        cout << i << " ";
    cout << endl;

    cout << "c4 = ";
    for (int i : c4)
        cout << i << " ";
    cout << endl;

    cout << "c5 = ";
    for (int i : c5)
        cout << i << " ";
    cout << endl;

    cout << "c6 = ";
    for (int i : c6)
        cout << i << " ";
    cout << endl;

    // Move deque c6 to deque c7
    deque <int> c7(move(c6));
    deque <int>::iterator c7_Iter;

    cout << "c7 =";
    for (int i : c7)
        cout << i << " ";
    cout << endl;

    cout << "c8 = ";
    for (int i : c8)
        cout << i << " ";
    cout << endl;

    cout << "c9 = ";
    for (int i : c9)
        cout << i << " ";
    cout << endl;

    int x = 3;
}
// deque_deque.cpp
// compile with: /EHsc
#include <deque>
#include <iostream>

int main( ) 
{
    using namespace std;
   deque <int>::iterator c1_Iter, c2_Iter, c3_Iter, c4_Iter, c5_Iter, c6_Iter;

    // Create an empty deque c0
    deque <int> c0;

    // Create a deque c1 with 3 elements of default value 0
    deque <int> c1( 3 );

    // Create a deque c2 with 5 elements of value 2
    deque <int> c2( 5, 2 );

    // Create a deque c3 with 3 elements of value 1 and with the 
    // allocator of deque c2
    deque <int> c3( 3, 1, c2.get_allocator( ) );

    // Create a copy, deque c4, of deque c2
    deque <int> c4( c2 );

    // Create a deque c5 by copying the range c4[_First, _Last)
    c4_Iter = c4.begin( );
    c4_Iter++;
    c4_Iter++;
    deque <int> c5( c4.begin( ), c4_Iter );

    // Create a deque c6 by copying the range c4[_First, _Last) and 
    // c2 with the allocator of deque
    c4_Iter = c4.begin( );
   c4_Iter++;
   c4_Iter++;
   c4_Iter++;
   deque <int> c6( c4.begin( ), c4_Iter, c2.get_allocator( ) );

    // Create a deque c8 by copying the contents of an initializer_list
    // using brace initialization
    deque<int> c8({ 1, 2, 3, 4 });

        initializer_list<int> iList{ 5, 6, 7, 8 };
    deque<int> c9( iList);

    cout << "c1 = ";
    for ( c1_Iter = c1.begin( ); c1_Iter != c1.end( ); c1_Iter++ )
        cout << *c1_Iter << " ";
    cout << endl;
   
    cout << "c2 = ";
    for ( c2_Iter = c2.begin( ); c2_Iter != c2.end( ); c2_Iter++ )
        cout << *c2_Iter << " ";
    cout << endl;

    cout << "c3 = ";
    for ( c3_Iter = c3.begin( ); c3_Iter != c3.end( ); c3_Iter++ )
        cout << *c3_Iter << " ";
    cout << endl;

    cout << "c4 = ";
    for ( c4_Iter = c4.begin( ); c4_Iter != c4.end( ); c4_Iter++ )
        cout << *c4_Iter << " ";
    cout << endl;

    cout << "c5 = ";
    for ( c5_Iter = c5.begin( ); c5_Iter != c5.end( ); c5_Iter++ )
        cout << *c5_Iter << " ";
    cout << endl;

    cout << "c6 = ";
    for ( c6_Iter = c6.begin( ); c6_Iter != c6.end( ); c6_Iter++ )
        cout << *c6_Iter << " ";
    cout << endl;

    // Move deque c6 to deque c7
    deque <int> c7( move(c6) );
    deque <int>::iterator c7_Iter;
   
    cout << "c7 =" ;
    for ( c7_Iter = c7.begin( ) ; c7_Iter != c7.end( ) ; c7_Iter++ )
        cout << " " << *c7_Iter;
    cout << endl;

    cout << "c8 = ";
    for (int i : c8)
        cout << i << " ";
    cout << endl;

    cout << "c9 = ";
    or (int i : c9)
        cout << i << " ";
    cout << endl;
}

Output

c1 = 0 0 0
c2 = 2 2 2 2 2
c3 = 1 1 1
c4 = 2 2 2 2 2
c5 = 2 2
c6 = 2 2 2
c7 = 2 2 2
c8 = 1 2 3 4
c9 = 5 6 7 8

Requirements

Header: <deque>

Namespace: std

See Also

Reference

deque Class

Standard Template Library