[libsigcplusplus] Replace some reinterpret_cast<>s with static_casts<>.

[Murray Cumming <murrayc src gnome org>]

commit ba9e84fa765e3bc7492f3cd12f8ebb463f2f7536
Author: Murray Cumming <murrayc murrayc com>
Date:   Sat Apr 16 21:29:37 2016 +0200

    Replace some reinterpret_cast<>s with static_casts<>.
    
    This is particularly unnecessary now that we have the notifiable
    base class.

 sigc++/connection.cc         |    2 +-
 sigc++/functors/slot.h       |    2 +-
 sigc++/functors/slot_base.cc |    4 ++--
 sigc++/functors/slot_base.h  |    2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)
---
diff --git a/sigc++/connection.cc b/sigc++/connection.cc
index 6772276..b7d3517 100644
--- a/sigc++/connection.cc
+++ b/sigc++/connection.cc
@@ -109,7 +109,7 @@ connection::set_slot(slot_base* sl)
 void
 connection::notify(notifiable* data)
 {
-  auto self = reinterpret_cast<connection*>(data);
+  auto self = static_cast<connection*>(data);
   self->slot_ = nullptr;
 }
 
diff --git a/sigc++/functors/slot.h b/sigc++/functors/slot.h
index df4f80e..a66f376 100644
--- a/sigc++/functors/slot.h
+++ b/sigc++/functors/slot.h
@@ -67,7 +67,7 @@ private:
    */
   static void destroy(notifiable* data)
   {
-    self* self_ = static_cast<self*>(reinterpret_cast<slot_rep*>(data));
+    self* self_ = static_cast<self*>(data);
     self_->call_ = nullptr;
     self_->destroy_ = nullptr;
     sigc::visit_each_trackable(slot_do_unbind(self_), self_->functor_);
diff --git a/sigc++/functors/slot_base.cc b/sigc++/functors/slot_base.cc
index 78130e2..a5cd529 100644
--- a/sigc++/functors/slot_base.cc
+++ b/sigc++/functors/slot_base.cc
@@ -29,7 +29,7 @@ struct destroy_notify_struct : public sigc::notifiable
 
   static void notify(notifiable* data) noexcept
   {
-    auto self_ = reinterpret_cast<destroy_notify_struct*>(data);
+    auto self_ = static_cast<destroy_notify_struct*>(data);
     self_->deleted_ = true;
   }
 
@@ -79,7 +79,7 @@ slot_rep::disconnect()
 void
 slot_rep::notify(notifiable* data)
 {
-  auto self_ = reinterpret_cast<slot_rep*>(data);
+  auto self_ = static_cast<slot_rep*>(data);
 
   self_->call_ = nullptr; // Invalidate the slot.
 
diff --git a/sigc++/functors/slot_base.h b/sigc++/functors/slot_base.h
index 8bc5dc9..7ad2d51 100644
--- a/sigc++/functors/slot_base.h
+++ b/sigc++/functors/slot_base.h
@@ -98,7 +98,7 @@ public:
    */
   inline slot_rep* dup() const
   {
-    return reinterpret_cast<slot_rep*>((*dup_)(const_cast<slot_rep*>(this)));
+    return static_cast<slot_rep*>((*dup_)(const_cast<slot_rep*>(this)));
   }
 
   /** Set the parent with a callback.