Can range based for loop work over a range

Question

If I have range (pair of 2 iterators) is there a way to write \"for each\" loop for that uses range, not a raw array or container.

Something like this:

Answer 1

#include 
#include 
#include 

template 
struct range_adapter {
    std::pair p;

    range_adapter(const std::pair &p) : p(p) {}

    I begin() const { return p.first; }
    I end() const { return p.second; }
};

template 
range_adapter in_range(const std::pair &p)
{
    return range_adapter(p);
}

int main()
{
    std::vector data { 1, 2, 2, 3, 3, 3, 4 };

    auto r = std::equal_range(data.begin(), data.end(), 2);

    for (const auto &elem : in_range(r))
    {
        std::cout << elem << std::endl;
    }
}