In filtered_graph.hpp there appear to be a number of predefined
predicates for general use (they are no in the detail namespace).  One
of them that I'd like to use is is_in_subset, but it appears that
set_contains is not defined anywhere, not even for the most common
case (std::set).

Shouldn't Boost provide something like

template <typename T, typename L, typename A, typename E>
bool set_contains(const std::set<T, L, A> &s, const E &e)
{
       return s.find(e) != s.end();
}

and vice-versa for is_not_in_subset so that users don't have to open
up the boost namespace and define it themselves?