MSVC build: Silence 'C4100: unreferenced formal parameter' warnings

Stuart Dootson · murraycu · commit e82f0d341b56 · 2019-10-25T12:57:31.000+02:00
Added 'static_cast&lt;void&gt;(parameter-name)' in all paths where the parameter isn't used
diff --git a/sigc++/tuple-utils/tuple_end.h b/sigc++/tuple-utils/tuple_end.h
@@ -56,6 +56,7 @@ tuple_end(T&& t) {
   static_assert(len <= size, "The tuple size must be less than or equal to the length.");
 
   if constexpr(len == 0) {
+    static_cast<void>(t);
     // Recursive calls to tuple_cdr() would result in this eventually,
     // but this avoids the extra work:
     return std::tuple<>();
diff --git a/sigc++/tuple-utils/tuple_for_each.h b/sigc++/tuple-utils/tuple_for_each.h
@@ -103,6 +103,8 @@ tuple_for_each(T&& t, T_extras&&... extras)
   {
     detail::tuple_for_each_impl<T_visitor, size, T_extras...>::tuple_for_each(
       std::forward<T>(t), std::forward<T_extras>(extras)...);
+  } else {
+    static_cast<void>(t);
   }
 }
 
diff --git a/sigc++/tuple-utils/tuple_transform_each.h b/sigc++/tuple-utils/tuple_transform_each.h
@@ -35,6 +35,7 @@ struct tuple_transform_each_impl {
   static decltype(auto)
   tuple_transform_each(T_current&& t, T_original& t_original) {
     if constexpr(size_from_index == 0) {
+      static_cast<void>(t_original);
       //Do nothing because the tuple has no elements.
       return std::forward<T_current>(t);
     } else { //TODO: Should this compile without using else to contain the alternative code?
diff --git a/sigc++/visit_each.h b/sigc++/visit_each.h
@@ -47,6 +47,8 @@ struct limit_trackable_target
     //Only call action_() if T_Type derives from trackable.
     if constexpr(is_base_of_or_same_v<sigc::trackable, T_type>) {
         std::invoke(action_, type);
+    } else {
+      static_cast<void>(type);
     }
   }
 

Original file line number	Diff line number	Diff line change
`@@ -103,6 +103,8 @@ tuple_for_each(T&& t, T_extras&&... extras)`
`103`	`103`	`{`
`104`	`104`	`detail::tuple_for_each_impl<T_visitor, size, T_extras...>::tuple_for_each(`
`105`	`105`	`std::forward<T>(t), std::forward<T_extras>(extras)...);`
	`106`	`+ } else {`
	`107`	`+ static_cast<void>(t);`
`106`	`108`	`}`
`107`	`109`	`}`
`108`	`110`
Original file line number	Diff line number	Diff line change
`@@ -47,6 +47,8 @@ struct limit_trackable_target`
`47`	`47`	`//Only call action_() if T_Type derives from trackable.`
`48`	`48`	`if constexpr(is_base_of_or_same_v<sigc::trackable, T_type>) {`
`49`	`49`	`std::invoke(action_, type);`
	`50`	`+ } else {`
	`51`	`+ static_cast<void>(type);`
`50`	`52`	`}`
`51`	`53`	`}`
`52`	`54`