[BL] removed default args

BaseLib/ConfigTree.h

@@ -256,8 +256,8 @@ public:
      */
     explicit ConfigTree(PTree const& tree,
                            std::string const& filename,
-                           Callback const& error_cb = onerror,
-                           Callback const& warning_cb = onerror);
+                           Callback const& error_cb,
+                           Callback const& warning_cb);
 
     //! copying is not compatible with the semantics of this class
     ConfigTree(ConfigTree const&) = delete;

BaseLib/ConfigTreeUtil.cpp

@@ -21,6 +21,7 @@ ConfigTreeTopLevel::ConfigTreeTopLevel(
         ConfigTree::PTree&& ptree)
     : _ptree(std::move(ptree))
     , _ctree(_ptree, filepath,
+             ConfigTree::onerror,
              be_ruthless ? ConfigTree::onerror : ConfigTree::onwarning)
 {
 }