C++ Deque Library - deque() Function

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Description

The C++ fill constructor std::deque::deque() construct a new deque with n elements and assign val to each element of deque. For C++11 constructor if val is not provided default value is zero. Storage requirement for this container is fulfilled by internal allocator.

Declaration

Following is the declaration for std::deque::deque() constructor form std::deque header.

C++98

explicit deque (size_type n, const value_type& val = value_type(),
                  const allocator_type& alloc = allocator_type());

C++11

explicit deque (size_type n);

deque (size_type n, const value_type& val,
         const allocator_type& alloc = allocator_type());

Parameters

• alloc − The allocator object.

• n − Number of elements to be inserted into container.

• val − Value to be assigned to each element of the container.

Return value

Constructor never returns value.

Exceptions

This member function never throws exception.

Time complexity

Linear i.e. O(n)

Example

The following example shows the usage of std::deque::deque() constructor.

#include <iostream>
#include <deque>

using namespace std;

int main(void) {

   deque<int> d(5, 1);

   cout << "Contents of deque are" << endl;

   for (int i = 0; i < d.size(); ++i)
      cout << d[i] << endl;

   return 0;
}

Let us compile and run the above program, this will produce the following result −

Contents of deque are
1
1
1
1
1