Add helper function for removing objects from STL containers. mem_fun() and mem_fun_ref() are handy for using const (?) member functions as predicates.

stepmania/src/RageUtil.h

@@ -95,6 +95,18 @@ void CircularShift( vector<T> &v, int dist )
 	}
 }
 
+/*
+ * Helper function to remove all objects from an STL container for which the
+ * Predicate pred is true. If you want to remove all objects for which the predicate
+ * returns false, wrap the predicate with not1().
+ */
+template<typename Container, typename Predicate>
+inline void RemoveIf( Container& c, Predicate p )
+{
+	c.erase( remove_if(c.begin(), c.end(), p), c.end() );
+}
+
+
 /*
  * We only have unsigned swaps; byte swapping a signed value doesn't make sense. 
  *