Add same root assertion for link and lowest_common_ancestor; Move typename outside of template

Author: yi-ji

include/boost/graph/link_cut_trees.hpp

@@ -38,8 +38,9 @@ namespace boost
         }
 
         template <class Element>
-        inline void link(Element x, Element y) // Element x must be a tree root
+        inline void link(Element x, Element y)
         {
+            BOOST_ASSERT(find_root(x) == x); // Element x must be a tree root
             Element r = expose(x);
             r = join(r, r, expose(y));
             put_successor(r, r);
@@ -55,8 +56,9 @@ namespace boost
         }
 
         template <class Element>
-        inline Element lowest_common_ancestor(Element x, Element y) // Elements x and y must have same root
+        inline Element lowest_common_ancestor(Element x, Element y)
         {
+            BOOST_ASSERT(find_root(x) == find_root(y)); // Elements x and y must have same root
             expose(x);
             return expose(y);
         }

test/link_cut_trees_test.cpp

@@ -194,7 +194,8 @@ BOOST_AUTO_TEST_CASE(link_cut_trees_test6)
 {
     typedef associative_property_map< std::map<std::string, int> > id_map_t;
     typedef vector_property_map<std::string> inverse_id_map_t;
-    typedef link_cut_trees_with_storage<id_map_t, inverse_id_map_t, typename std::map<int, int> > link_cut_trees_t;
+    typedef std::map<int, int> index_map_container_t;
+    typedef link_cut_trees_with_storage<id_map_t, inverse_id_map_t, index_map_container_t> link_cut_trees_t;
     std::vector<std::string> elements;
     std::vector<int> numbers(100);
     std::map<std::string, int> id_map;