What are the differences between C++20 ranges and traditional iterators?

What are the differences between C++20 ranges and traditional iterators?

C++20 introduces ranges, which provide a more expressive and convenient way to work with sequences compared to traditional iterators. Ranges allow for more readable code and can eliminate some common iterator-related errors.

Can you give me an example of using ranges?

Sure! Here's a simple example: instead of using a loop with iterators to filter a vector, you can use ranges like this:

#include <ranges>
#include <vector>
#include <iostream>

int main() {
    std::vector<int> numbers = {1, 2, 3, 4, 5};
    auto even_numbers = numbers | std::views::filter([](int n) { return n % 2 == 0; });
    for (int n : even_numbers) {
        std::cout << n << ' ';
    }
}

This code filters even numbers from the vector using ranges.

What are the advantages of using ranges over iterators?

Ranges provide several advantages: they improve code readability, reduce boilerplate code, and help prevent common mistakes like dereferencing invalid iterators. They also support lazy evaluation, which can lead to performance improvements.

Are there any downsides to using ranges?

One downside is that ranges may have a steeper learning curve for those familiar with traditional iterators. Additionally, not all existing libraries and algorithms are compatible with ranges yet, so you might encounter limitations in some cases.