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

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