visit<>(): drop the overload for pointer-like objects

It confuses compilers and adds a mostly unneeded null check; it's dead easy
to just dereference a pointer before passing it to visit<>().

2 files changed, 17 insertions, 25 deletions

diff --git a/lib/events/event.h b/lib/events/event.h
index 12903274..7fd9868d 100644
--- a/lib/events/event.h
+++ b/lib/events/event.h
@@ -315,10 +315,11 @@ namespace QMatrixClient
 
     // A single type-specific void visitor
     template <typename BaseEventT, typename FnT>
-    inline auto visit(const BaseEventT& event, FnT&& visitor)
-        -> std::enable_if_t<
-            is_event_v<BaseEventT> && needs_cast_v<BaseEventT, FnT> &&
-            std::is_void<fn_return_t<FnT>>::value>
+    inline
+    std::enable_if_t<
+        is_event_v<BaseEventT> && needs_cast_v<BaseEventT, FnT> &&
+        std::is_void<fn_return_t<FnT>>::value>
+    visit(const BaseEventT& event, FnT&& visitor)
     {
         using event_type = fn_arg_t<FnT>;
         if (is<event_type>(event))
@@ -327,11 +328,12 @@ namespace QMatrixClient
 
     // A single type-specific non-void visitor with an optional default value
     template <typename BaseEventT, typename FnT>
-    inline auto visit(const BaseEventT& event, FnT&& visitor,
-                      fn_return_t<FnT>&& defaultValue = {})
-        -> std::enable_if_t<
-            is_event_v<BaseEventT> && needs_cast_v<BaseEventT, FnT>,
-            fn_return_t<FnT>> // non-voidness is guarded by defaultValue type
+    inline
+    std::enable_if_t<
+        is_event_v<BaseEventT> && needs_cast_v<BaseEventT, FnT>,
+        fn_return_t<FnT>> // non-voidness is guarded by defaultValue type
+    visit(const BaseEventT& event, FnT&& visitor,
+          fn_return_t<FnT>&& defaultValue = {})
     {
         using event_type = fn_arg_t<FnT>;
         if (is<event_type>(event))
@@ -341,9 +343,10 @@ namespace QMatrixClient
 
     // A chain of 2 or more visitors
     template <typename BaseEventT, typename FnT1, typename FnT2, typename... FnTs>
-    inline auto visit(const BaseEventT& event, FnT1&& visitor1,
-                      FnT2&& visitor2, FnTs&&... visitors)
-        -> std::enable_if_t<is_event_v<BaseEventT>, fn_return_t<FnT1>>
+    inline
+    std::enable_if_t<is_event_v<BaseEventT>, fn_return_t<FnT1>>
+    visit(const BaseEventT& event, FnT1&& visitor1, FnT2&& visitor2,
+          FnTs&&... visitors)
     {
         using event_type1 = fn_arg_t<FnT1>;
         if (is<event_type1>(event))
@@ -351,17 +354,6 @@ namespace QMatrixClient
         return visit(event, std::forward<FnT2>(visitor2),
                      std::forward<FnTs>(visitors)...);
     }
-
-    // An adaptor accepting a pointer-like object instead of an event
-    template <typename EventHolderT, typename... FnTs>
-    inline auto visit(const EventHolderT& e, FnTs&&... visitors)
-        -> decltype(visit(*e, std::forward<FnTs>(visitors)...))
-    {
-        using return_type = decltype(visit(*e, std::forward<FnTs>(visitors)...));
-        if (e)
-            return visit(*e, std::forward<FnTs>(visitors)...);
-        return return_type();
-    }
 }  // namespace QMatrixClient
 Q_DECLARE_METATYPE(QMatrixClient::Event*)
 Q_DECLARE_METATYPE(const QMatrixClient::Event*)
diff --git a/lib/room.cpp b/lib/room.cpp
index 080ad30d..dc9f5ccc 100644
--- a/lib/room.cpp
+++ b/lib/room.cpp
@@ -1530,7 +1530,7 @@ bool Room::processStateEvent(const RoomEvent& e)
 void Room::processEphemeralEvent(EventPtr&& event)
 {
     QElapsedTimer et; et.start();
-    visit(event
+    visit(*event
         , [this,et] (const TypingEvent& evt) {
             d->usersTyping.clear();
             for( const QString& userId: qAsConst(evt.users()) )
@@ -1595,7 +1595,7 @@ void Room::processEphemeralEvent(EventPtr&& event)
 
 void Room::processAccountDataEvent(EventPtr&& event)
 {
-    visit(event
+    visit(*event
         , [this] (const TagEvent& evt) {
             auto newTags = evt.tags();
             if (newTags == d->tags)