This is a kind of follow-up question to How to detect a template function should impose a more strict concept.

I have some code that looks like this:

#include <iterator>

template<std::random_access_iterator Iter>
auto compare(Iter i1, Iter i2)
{
    return i1 < i2;
}

I then realise I can replace less than with not equal to:

template<std::random_access_iterator Iter>
auto compare(Iter i1, Iter i2)
{
    return i1 != i2;
}

Now the concept constrain can be downgraded to forward_iterator. Is there a way to help me detect this, apart from a careful code review?