Add missing perfect forwarding in mem_functor and pointer_functor

slavaandrejev · kjellahl · commit cc857baa5aac · 2021-12-23T10:18:18.000+01:00
This is a missed addition to the commit that allowed rvalue references
in slot parameters.
diff --git a/sigc++/functors/mem_fun.h b/sigc++/functors/mem_fun.h
@@ -113,7 +113,7 @@ class mem_functor
    */
   decltype(auto) operator()(obj_type_with_modifier& obj, type_trait_take_t<T_arg>... a) const
   {
-    return std::invoke(func_ptr_, obj, a...);
+    return std::invoke(func_ptr_, obj, std::forward<type_trait_take_t<T_arg>>(a)...);
   }
 
 protected:
diff --git a/sigc++/functors/ptr_fun.h b/sigc++/functors/ptr_fun.h
@@ -92,7 +92,9 @@ class pointer_functor<T_return(T_args...)>
    * @param a Arguments to be passed on to the function.
    * @return The return value of the function invocation.
    */
-  T_return operator()(type_trait_take_t<T_args>... a) const { return std::invoke(func_ptr_, a...); }
+  T_return operator()(type_trait_take_t<T_args>... a) const {
+    return std::invoke(func_ptr_, std::forward<type_trait_take_t<T_args>>(a)...);
+  }
 };
 
 /** Creates a functor of type sigc::pointer_functor which wraps an existing non-member function.
diff --git a/tests/test_rvalue_ref.cc b/tests/test_rvalue_ref.cc
@@ -21,6 +21,9 @@ struct A
   void foo(MoveableStruct &&) { result_stream << "A::foo(MoveableStruct&&)"; }
 };
 
+void boo(MoveableStruct &&) {
+  result_stream << "boo(MoveableStruct&&)";
+}
 
 } // end anonymous namespace
 
@@ -48,6 +51,17 @@ test_slot()
 
 void
 test_mem_fun()
+{
+  sigc::slot<void(A &, MoveableStruct &&)> slot;
+  A a;
+  slot = sigc::mem_fun(&A::foo);
+  MoveableStruct x;
+  slot(a, std::move(x));
+  util->check_result(result_stream, "A::foo(MoveableStruct&&)");
+}
+
+void
+test_bound_mem_fun()
 {
   sigc::slot<void(MoveableStruct &&)> slot;
   A a;
@@ -57,6 +71,16 @@ test_mem_fun()
   util->check_result(result_stream, "A::foo(MoveableStruct&&)");
 }
 
+void
+test_ptr_fun()
+{
+  sigc::slot<void(MoveableStruct &&)> slot;
+  slot = sigc::ptr_fun(&boo);
+  MoveableStruct x;
+  slot(std::move(x));
+  util->check_result(result_stream, "boo(MoveableStruct&&)");
+}
+
 int
 main(int argc, char* argv[])
 {
@@ -66,7 +90,9 @@ main(int argc, char* argv[])
 
   test_signal();
   test_slot();
+  test_bound_mem_fun();
   test_mem_fun();
+  test_ptr_fun();
 
   return util->get_result_and_delete_instance() ? EXIT_SUCCESS : EXIT_FAILURE;
 } // end main()

Original file line number	Diff line number	Diff line change
`@@ -113,7 +113,7 @@ class mem_functor`
`113`	`113`	`*/`
`114`	`114`	`decltype(auto) operator()(obj_type_with_modifier& obj, type_trait_take_t<T_arg>... a) const`
`115`	`115`	`{`
`116`		`- return std::invoke(func_ptr_, obj, a...);`
	`116`	`+ return std::invoke(func_ptr_, obj, std::forward<type_trait_take_t<T_arg>>(a)...);`
`117`	`117`	`}`
`118`	`118`
`119`	`119`	`protected:`