In C++, you can create a deque using the std::deque template class from the Standard Template Library (STL). Here is an example of how to create a deque:

#include <deque>
#include <iostream>

int main() {
    std::deque<int> d {1, 2, 3, 4, 5}; // create a deque with 5 elements
    d.push_back(6); // add an element to the back of the deque
    d.push_front(0); // add an element to the front of the deque

    for (int i : d) {
        std::cout << i << " "; // output the elements of the deque
    }
    std::cout << std::endl;

    return 0;
}

Output:

0 1 2 3 4 5 6

In this example, we include the <deque> header file to use the std::deque template class. We then create a deque d with five elements using the initialization list syntax. We add an element to the back of the deque using the push_back() method, and an element to the front of the deque using the push_front() method. Finally, we use a range-based for loop to output the elements of the deque to the console.

You can also create an empty deque and add elements to it later using the push_back() and push_front() methods, or the emplace_back() and emplace_front() methods to construct and insert elements in place.