--- a/libinterp/parse-tree/pt-check.h	Thu Jan 19 14:47:19 2017 -0500
+++ b/libinterp/parse-tree/pt-check.h	Thu Jan 19 23:41:54 2017 -0500
@@ -27,120 +27,128 @@
 
 #include "pt-walk.h"
 
-class tree_decl_command;
-
-// How to check the semantics of the code that the parse trees represent.
-
-class
-tree_checker : public tree_walker
+namespace octave
 {
-public:
+  class tree_decl_command;
+
+  // How to check the semantics of the code that the parse trees represent.
 
-  tree_checker (void)
-    : do_lvalue_check (false), file_name () { }
+  class tree_checker : public tree_walker
+  {
+  public:
 
-  // No copying!
+    tree_checker (void)
+      : do_lvalue_check (false), file_name () { }
 
-  tree_checker (const tree_checker&) = delete;
+    // No copying!
+
+    tree_checker (const tree_checker&) = delete;
 
-  tree_checker& operator = (const tree_checker&) = delete;
+    tree_checker& operator = (const tree_checker&) = delete;
 
-  ~tree_checker (void) = default;
+    ~tree_checker (void) = default;
 
-  void visit_argument_list (tree_argument_list&);
+    void visit_argument_list (tree_argument_list&);
 
-  void visit_binary_expression (tree_binary_expression&);
+    void visit_binary_expression (tree_binary_expression&);
 
-  void visit_break_command (tree_break_command&);
+    void visit_break_command (tree_break_command&);
 
-  void visit_colon_expression (tree_colon_expression&);
+    void visit_colon_expression (tree_colon_expression&);
 
-  void visit_continue_command(tree_continue_command&);
+    void visit_continue_command(tree_continue_command&);
+
+    void visit_global_command (tree_global_command&);
 
-  void visit_global_command (tree_global_command&);
+    void visit_persistent_command (tree_persistent_command&);
 
-  void visit_persistent_command (tree_persistent_command&);
+    void visit_decl_elt (tree_decl_elt&);
 
-  void visit_decl_elt (tree_decl_elt&);
+    void visit_decl_init_list (tree_decl_init_list&);
 
-  void visit_decl_init_list (tree_decl_init_list&);
+    void visit_simple_for_command (tree_simple_for_command&);
 
-  void visit_simple_for_command (tree_simple_for_command&);
+    void visit_complex_for_command (tree_complex_for_command&);
 
-  void visit_complex_for_command (tree_complex_for_command&);
+    void visit_octave_user_script (octave_user_script&);
 
-  void visit_octave_user_script (octave_user_script&);
+    void visit_octave_user_function (octave_user_function&);
+
+    void visit_function_def (tree_function_def&);
 
-  void visit_octave_user_function (octave_user_function&);
+    void visit_identifier (tree_identifier&);
 
-  void visit_function_def (tree_function_def&);
+    void visit_if_clause (tree_if_clause&);
 
-  void visit_identifier (tree_identifier&);
+    void visit_if_command (tree_if_command&);
 
-  void visit_if_clause (tree_if_clause&);
+    void visit_if_command_list (tree_if_command_list&);
 
-  void visit_if_command (tree_if_command&);
+    void visit_index_expression (tree_index_expression&);
 
-  void visit_if_command_list (tree_if_command_list&);
+    void visit_matrix (tree_matrix&);
 
-  void visit_index_expression (tree_index_expression&);
+    void visit_cell (tree_cell&);
 
-  void visit_matrix (tree_matrix&);
+    void visit_multi_assignment (tree_multi_assignment&);
 
-  void visit_cell (tree_cell&);
+    void visit_no_op_command (tree_no_op_command&);
 
-  void visit_multi_assignment (tree_multi_assignment&);
+    void visit_anon_fcn_handle (tree_anon_fcn_handle&);
 
-  void visit_no_op_command (tree_no_op_command&);
+    void visit_constant (tree_constant&);
 
-  void visit_anon_fcn_handle (tree_anon_fcn_handle&);
+    void visit_fcn_handle (tree_fcn_handle&);
 
-  void visit_constant (tree_constant&);
+    void visit_funcall (tree_funcall&);
 
-  void visit_fcn_handle (tree_fcn_handle&);
+    void visit_parameter_list (tree_parameter_list&);
+
+    void visit_postfix_expression (tree_postfix_expression&);
 
-  void visit_funcall (tree_funcall&);
+    void visit_prefix_expression (tree_prefix_expression&);
 
-  void visit_parameter_list (tree_parameter_list&);
+    void visit_return_command (tree_return_command&);
 
-  void visit_postfix_expression (tree_postfix_expression&);
+    void visit_return_list (tree_return_list&);
 
-  void visit_prefix_expression (tree_prefix_expression&);
+    void visit_simple_assignment (tree_simple_assignment&);
 
-  void visit_return_command (tree_return_command&);
+    void visit_statement (tree_statement&);
 
-  void visit_return_list (tree_return_list&);
+    void visit_statement_list (tree_statement_list&);
 
-  void visit_simple_assignment (tree_simple_assignment&);
+    void visit_switch_case (tree_switch_case&);
 
-  void visit_statement (tree_statement&);
+    void visit_switch_case_list (tree_switch_case_list&);
 
-  void visit_statement_list (tree_statement_list&);
+    void visit_switch_command (tree_switch_command&);
 
-  void visit_switch_case (tree_switch_case&);
+    void visit_try_catch_command (tree_try_catch_command&);
 
-  void visit_switch_case_list (tree_switch_case_list&);
+    void visit_unwind_protect_command (tree_unwind_protect_command&);
 
-  void visit_switch_command (tree_switch_command&);
+    void visit_while_command (tree_while_command&);
 
-  void visit_try_catch_command (tree_try_catch_command&);
+    void visit_do_until_command (tree_do_until_command&);
 
-  void visit_unwind_protect_command (tree_unwind_protect_command&);
+  private:
 
-  void visit_while_command (tree_while_command&);
+    bool do_lvalue_check;
 
-  void visit_do_until_command (tree_do_until_command&);
+    std::string file_name;
 
-private:
+    void do_decl_command (tree_decl_command&);
 
-  bool do_lvalue_check;
-
-  std::string file_name;
+    OCTAVE_NORETURN void errmsg (const std::string& msg, int line);
+  };
+}
 
-  void do_decl_command (tree_decl_command&);
+#if defined (OCTAVE_USE_DEPRECATED_FUNCTIONS)
 
-  OCTAVE_NORETURN void errmsg (const std::string& msg, int line);
-};
+OCTAVE_DEPRECATED ("use 'octave::tree_checker' instead")
+typedef octave::tree_checker tree_checker;
 
 #endif
 
+#endif