Can C 11 Range-Based For Loops Iterate in Reverse?

Reverse Range-Based Iteration with C 11

Question:

Is there a way to reverse the direction of iterators for a range-based for-loop? Currently, transforming a standard for-loop with explicit iterators using rbegin() and rend() is possible, but it would be advantageous to have an analogous syntax for the range-based version.

Answer:

Rather than creating a custom adapter, Boost offers a convenient solution with boost::adaptors::reverse. This adapter reverses the order of elements while iterating.

Usage Example:

#include <list>
#include <iostream>
#include <boost/range/adaptor/reversed.hpp>

int main()
{
    std::list<int> x { 2, 3, 5, 7, 11, 13, 17, 19 };
    for (auto i : boost::adaptors::reverse(x))
        std::cout << i << '\n';
    for (auto i : x)
        std::cout << i << '\n';
}

The above is the detailed content of Can C 11 Range-Based For Loops Iterate in Reverse?. For more information, please follow other related articles on the PHP Chinese website!