19.20.27508.1 (from the latest VS 16.0.1, please notice the update) just
cannot compile it and g++ cannot compile it as the shared library. Static
FnGraph example is about 100 MB in size for Debug build and this is
extremely inconvenient in practical work (link time is too big that is why
I would prefer shared build).

template <class Range>
using value_type_of = typename std::remove_reference<decltype(*((typename std::remove_reference<Range>::type *)0)->begin())>::type;

void foo()
{
	std::less<value_type_of<std::set<int>>> z;
}