[libsigcplusplus] adapts, typed_slot_rep: Make adaptor_type aliases private.

[Murray Cumming <murrayc src gnome org>]

commit a018cb24d44c8ff4fd732a4bd0ea05cffb37d950
Author: Murray Cumming <murrayc murrayc com>
Date:   Wed Apr 13 22:40:10 2016 +0200

    adapts, typed_slot_rep: Make adaptor_type aliases private.
    
    They are used in public API, but that is legal C++.
    This way, we don't need to think that the public types are needed.

 sigc++/adaptors/adapts.h |    2 ++
 sigc++/functors/slot.h   |    2 +-
 2 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/sigc++/adaptors/adapts.h b/sigc++/adaptors/adapts.h
index a88461d..956b4b4 100644
--- a/sigc++/adaptors/adapts.h
+++ b/sigc++/adaptors/adapts.h
@@ -75,8 +75,10 @@ namespace sigc
 template <class T_functor>
 struct adapts : public adaptor_base
 {
+private:
   using adaptor_type = typename adaptor_trait<T_functor>::adaptor_type;
 
+public:
   /** Constructs an adaptor that wraps the passed functor.
    * @param _A_functor Functor to invoke from operator()().
    */
diff --git a/sigc++/functors/slot.h b/sigc++/functors/slot.h
index 4dacb87..ca1a211 100644
--- a/sigc++/functors/slot.h
+++ b/sigc++/functors/slot.h
@@ -25,10 +25,10 @@ struct typed_slot_rep : public slot_rep
 private:
   using self = typed_slot_rep<T_functor>;
 
-public:
   /* Use an adaptor type so that arguments can be passed as const references
    * through explicit template instantiation from slot_call#::call_it() */
   using adaptor_type = typename adaptor_trait<T_functor>::adaptor_type;
+public:
 
   /** The functor contained by this slot_rep object. */
   adaptor_type functor_;