binary_function is removed from equal and unary_function removed from tests.

include/boost/algorithm/cxx14/equal.hpp

@@ -27,7 +27,7 @@ namespace boost { namespace algorithm {
 namespace detail {
 
     template <class T1, class T2>
-    struct eq : public std::binary_function<T1, T2, bool> {
+    struct eq {
         BOOST_CONSTEXPR bool operator () ( const T1& v1, const T2& v2 ) const { return v1 == v2 ;}
         };