better use of templates for action_container and derived classes It should now be possible to add arbitrary lambda functions or std::function objects to the unwind_protect objects and octave_link event queues, and to add functions (including member functions) with any number of parameters. * action-container.h (action_container::fcn_elem): Define using variadic template, std::bind, and std::function for more flexibility and to eliminate code duplication. (action_container::method_elem, action_container::method_arg_elem, action_container::method_crefarg_elem, action_container::method_arg2_elem, action_container::method_arg3_elem, action_container::method_arg4_elem): Delete. (action_container::add_action): Rename from add. Now protected. (action_container::add): New generic function for adding functions. (action_container::add_fcn, action_container::add_method): Define using variadic template for more flexibility and to eliminate code duplication. * event-queue.h (event_queue::add_action): Rename from add. Now protected. * unwind-prot.h (unwind_protect::add_action): Likewise. * variable-editor-model.cc: Eliminate template parameters for calls to octave_link::post_event fucntions. * octave-link.h (octave_link::post_event, octave_link::do_post_event): Define using variadic template for more flexibility and to eliminate code duplication. * pt-eval.h, pt-eval.cc (tree_evaluator::uwp_set_echo_state): New function. (tree_evaluator::set_echo_state, tree_evaluator::set_echo_file_name, tree_evaluator::set_echo_file_pos): Delete. (tree_evaluator::push_echo_state_cleanup): Use uwp_set_echo_state instead of set_echo_state, set_echo_file_name, and set_echo_file_pos.

--- a/libinterp/parse-tree/pt-eval.h	Fri Jul 20 13:09:19 2018 -0700
+++ b/libinterp/parse-tree/pt-eval.h	Fri Jul 20 18:38:03 2018 -0400
@@ -538,19 +538,8 @@
     std::list<octave_lvalue> make_lvalue_list (tree_argument_list *);
 
     // For unwind-protect.
-    void set_echo_state (bool val) { m_echo_state = val; }
-
-    // For unwind-protect.
-    void set_echo_file_name (const std::string& file_name)
-    {
-      m_echo_file_name = file_name;
-    }
-
-    // For unwind-protect.
-    void set_echo_file_pos (const size_t& file_pos)
-    {
-      m_echo_file_pos = file_pos;
-    }
+    void uwp_set_echo_state (bool state, const std::string& file_name,
+                             size_t pos);
 
     bool echo_this_file (const std::string& file, int type) const;