Using std::ranges Algorithms with C-Style Arrays

Yes, you can use std::ranges algorithms with C-style arrays in C++. The std::ranges algorithms are designed to work with any range, including C-style arrays, as long as the range provides the necessary iterator support.

Example: Sorting a C-Style Array

Here’s an example of using std::ranges::sort() to sort a C-style array:

1#include <algorithm>
2#include <iostream>
3#include <ranges>
4
5int main() {
6  int numbers[] = {3, 1, 4, 1, 5, 9};
7
8  // Sorting the C-style array
9  std::ranges::sort(numbers);
10
11  // Printing the sorted array
12  for (const int& num : numbers) {
13    std::cout << num << " ";
14  }
15}

11 1 3 4 5 9

How It Works

• Including the Header: Include the <algorithm> and <ranges> headers to access the std::ranges algorithms.
• Using std::ranges::sort(): The std::ranges::sort() function can be used directly with the C-style array because arrays decay to pointers, providing the necessary iterator support.

Practical Considerations

• Array Size: The size of the C-style array must be known at compile time. You can use std::size(numbers) to get the number of elements in the array if you need to pass the size explicitly.
• Performance: Using std::ranges algorithms with C-style arrays provides the same performance benefits as using them with standard containers like std::vector or std::array.

Example: Applying Other Algorithms

You can use various std::ranges algorithms with C-style arrays. Here’s an example of using std::ranges::reverse() to reverse the elements of a C-style array:

1#include <algorithm>
2#include <iostream>
3#include <ranges>
4
5int main() {
6  int numbers[] = {3, 1, 4, 1, 5, 9};
7
8  // Reversing the C-style array
9  std::ranges::reverse(numbers);
10
11  // Printing the reversed array
12  for (const int& num : numbers) {
13    std::cout << num << " ";
14  }
15}

19 5 1 4 1 3

Conclusion

Using std::ranges algorithms with C-style arrays is straightforward and efficient. The algorithms provide a consistent and powerful interface for manipulating ranges, regardless of whether they are standard containers or C-style arrays.

This flexibility allows you to leverage the full power of the C++ standard library in a wide range of applications.