function for finding last item less-than-or-equal to, like lower_bound

Question

Is there a function in that uses binary search, like lower_bound but that returns the last item less-than-or-equal-to according to a given predic

Answer 1

I have test your reverse iterator solution, it is correct.

Given v is sorted by '<'

Find last element less than x:

auto iter = std::upper_bound(v.rbegin(), v.rend(), x, std::greater());
if(iter == v.rend())
    std::cout<<"no found";
else
    std::cout<<*iter;

Find last element less than equal x:

auto iter = std::lower_bound(v.rbegin(), v.rend(), x, std::greater());
if(iter == v.rend())
    std::cout<<"no found";
else
    std::cout<<*iter;

This is better than iter -= 1 version