Using std::ranges::subrange with Non-Standard Containers

Yes, you can use std::ranges::subrange with non-standard containers as long as the container provides iterators. The std::ranges::subrange template is designed to be flexible and work with any type of iterator, not just those from standard containers.

Requirements

To use std::ranges::subrange, your non-standard container must:

• Provide begin() and end() member functions that return iterators.
• Have iterators that meet the requirements of the standard iterator concepts.

Example with a Custom Container

Here's an example of how you might use std::ranges::subrange with a custom container:

1#include <iostream>
2#include <ranges>
3#include <vector>
4
5class CustomContainer {
6 public:
7  using iterator = std::vector<int>::iterator;
8  using const_iterator =
9    std::vector<int>::const_iterator;
10
11  CustomContainer(std::initializer_list<int> list)
12    : data_(list) {}
13
14  iterator begin() {
15    return data_.begin(); }
16  iterator end() {
17    return data_.end(); }
18  const_iterator begin() const {
19    return data_.begin(); }
20  const_iterator end() const {
21    return data_.end(); }
22
23 private:
24  std::vector<int> data_;
25};
26
27int main() {
28  CustomContainer container{1, 2, 3, 4, 5};
29  std::ranges::subrange view{
30    container.begin(), container.end()};
31
32  for (int n : view) {
33    std::cout << n << ", ";
34  }
35}

11, 2, 3, 4, 5,

Benefits

Using std::ranges::subrange with non-standard containers allows you to:

• Leverage the powerful range-based algorithms and views.
• Create subviews of your custom container without modifying it.
• Maintain compatibility with standard library functions.

Practical Considerations

• Ensure your container's iterators comply with the expected iterator concepts.
• Test thoroughly to make sure your custom iterators work correctly with std::ranges::subrange.

Advanced Usage

For more advanced usage, such as bidirectional or random access iterators, ensure your custom container's iterators implement the necessary operations (e.g., operator-- for bidirectional, operator[] for random access).

By following these guidelines, you can effectively use std::ranges::subrange with non-standard containers and benefit from the flexibility it provides.