Accessing next element in range based for loop before the next loop

Question

How do I access the next element in range based for loop before the next loop?

I know with an iterative approach you do something like arr[++i], but how do I achieve the same result in a range-based for loop?

for (auto& cmd : arr) {
   steps = nextElement; //How do I get this nextElement before the next loop?
}

I understand I probably shouldn't be using a range-based for loop, but that's the requirement provided for this project.

Answer 1

If the range has contiguous storage (e.g. std::vector, std::array, std::basic_string or a native array), then you can do this:

for (auto& cmd : arr) {
    steps = *(&cmd + 1);
}

Otherwise, you can't, without an external variable.