optimized RBTree: avoid unnecessary virtual RBTree and RBEntry implementation classes

 * whenever the implementation class was not exactly RBEntryType,
   it had to have a virtual destructor since RBTree cared about
   cleanup and had to delete its members.
 * Since it does not allocate them, it is consistent to remove RBTree::clear().
   The destructor now only checks that subclasses have cleaned up.
   Implementing cleanup in the subclasses is trivial.
 * Consequently, RBEntryString no longer has to be virtual.
   HelpIndex and GotoTables are completely non-virtual now
   which saves memory (and a bit of cleanup speed).
   For QRegister, not much changes, though.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/rbtree.cpp b/src/rbtree.cpp
index 5b1a4e1..79c63d6 100644
--- a/src/rbtree.cpp
+++ b/src/rbtree.cpp
@@ -48,7 +48,7 @@ auto_complete(const gchar *key, gchar completed, gsize restrict_len)
 
 	for (RBEntryString *cur = nfind(key);
 	     cur && !StringNCmp(cur->key, key, key_len);
-	     cur = (RBEntryString *)cur->next()) {
+	     cur = cur->next()) {
 		if (restrict_len && strlen(cur->key) != restrict_len)
 			continue;
 
@@ -68,7 +68,7 @@ auto_complete(const gchar *key, gchar completed, gsize restrict_len)
 	if (!insert && prefixed_entries > 1) {
 		for (RBEntryString *cur = first;
 		     cur && !StringNCmp(cur->key, key, key_len);
-		     cur = (RBEntryString *)cur->next()) {
+		     cur = cur->next()) {
 			if (restrict_len && strlen(cur->key) != restrict_len)
 				continue;