Is there a container adapter that would reverse the direction of iterators so I can iterate over a container in reverse with range-based for-loop?
With explicit iterators I would convert this:
for (auto i = c.begin(); i != c.end(); ++i) { ...
into this:
for (auto i = c.rbegin(); i != c.rend(); ++i) { ...
I want to convert this:
for (auto& i: c) { ...
to this:
for (auto& i: std::magic_reverse_adapter(c)) { ...
Is there such a thing or do I have to write it myself?
Actually Boost does have such adaptor: boost::adaptors::reverse
.
#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';
}