Converting a View Back to a Standard Container

Converting a view back to a standard container like std::vector is straightforward. You can use the range-based constructor of std::vector to achieve this.

Here’s an example:

1#include <iostream>
2#include <ranges>
3#include <vector>
4
5int main() {
6  std::vector<int> Numbers{1, 2, 3, 4, 5};
7  auto View = std::views::take(Numbers, 3);
8
9  std::vector<int> NewContainer(
10    View.begin(), View.end());
11
12  for (int Num : NewContainer) {
13    std::cout << Num << ", ";
14  }
15}

11, 2, 3,

Explanation

• Create View: We create a view of the first three elements using std::views::take().
• Convert to std::vector: We use the range-based constructor of std::vector to initialize NewContainer with the elements of the view.
• Output: We then iterate over the new container to display its elements.

Advantages

• Efficiency: This method efficiently copies elements from the view to the new container.
• Simplicity: It leverages existing C++ mechanisms for range-based initialization.

This approach can be adapted to other standard containers, such as std::list or std::deque, using their range-based constructors in a similar manner.

For example, converting to a std::list:

1#include <iostream>
2#include <list>
3#include <ranges>
4#include <vector>
5
6int main() {
7  std::vector<int> Numbers{1, 2, 3, 4, 5};
8  auto View = std::views::take(Numbers, 3);
9
10  std::list NewContainer(View.begin(), View.end());
11
12  for (int Num : NewContainer) {
13    std::cout << Num << ", ";
14  }
15}

11, 2, 3,

Using this method, you can easily convert views back to any standard container type, preserving the benefits of views while enabling further manipulations or storage as needed.