MSVC build: Add code comments

4 files changed, 5 insertions, 0 deletions

diff --git a/sigc++/tuple-utils/tuple_end.h b/sigc++/tuple-utils/tuple_end.h
index 72526aa..6c47a34 100644
--- 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) {
+    // Prevent 'unreferenced formal parameter' warning from MSVC by 'using' t
     static_cast<void>(t);
     // Recursive calls to tuple_cdr() would result in this eventually,
     // but this avoids the extra work:
diff --git a/sigc++/tuple-utils/tuple_for_each.h b/sigc++/tuple-utils/tuple_for_each.h
index 8659d65..5296b70 100644
--- a/sigc++/tuple-utils/tuple_for_each.h
+++ b/sigc++/tuple-utils/tuple_for_each.h
@@ -104,6 +104,7 @@ 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 {
+    // Prevent 'unreferenced formal parameter' warning from MSVC by 'using' t
     static_cast<void>(t);
   }
 }
diff --git a/sigc++/tuple-utils/tuple_transform_each.h b/sigc++/tuple-utils/tuple_transform_each.h
index 8d73764..fa1f7a8 100644
--- a/sigc++/tuple-utils/tuple_transform_each.h
+++ b/sigc++/tuple-utils/tuple_transform_each.h
@@ -35,6 +35,8 @@ struct tuple_transform_each_impl {
   static decltype(auto)
   tuple_transform_each(T_current&& t, T_original& t_original) {
     if constexpr(size_from_index == 0) {
+    // Prevent 'unreferenced formal parameter' warning from MSVC by 'using'
+    // t_original
       static_cast<void>(t_original);
       //Do nothing because the tuple has no elements.
       return std::forward<T_current>(t);
diff --git a/sigc++/visit_each.h b/sigc++/visit_each.h
index 5f92120..032068a 100644
--- a/sigc++/visit_each.h
+++ b/sigc++/visit_each.h
@@ -48,6 +48,7 @@ struct limit_trackable_target
     if constexpr(is_base_of_or_same_v<sigc::trackable, T_type>) {
         std::invoke(action_, type);
     } else {
+    // Prevent 'unreferenced formal parameter' warning from MSVC by 'using' type
       static_cast<void>(type);
     }
   }