[libsigc++2/variadic] Remove deprecated SIGC_FUNCTORS_DEDUCE_RESULT_TYPE_WITH_DECLTYPE

[Murray Cumming <murrayc src gnome org>]

commit fd966a7c07687539ad8825cde3cbaf547fde6bda
Author: Murray Cumming <murrayc murrayc com>
Date:   Fri Jan 15 23:40:59 2016 +0100

    Remove deprecated SIGC_FUNCTORS_DEDUCE_RESULT_TYPE_WITH_DECLTYPE

 sigc++/functors/functor_trait.h |   23 -----------------------
 1 files changed, 0 insertions(+), 23 deletions(-)
---
diff --git a/sigc++/functors/functor_trait.h b/sigc++/functors/functor_trait.h
index 4487b50..54240be 100644
--- a/sigc++/functors/functor_trait.h
+++ b/sigc++/functors/functor_trait.h
@@ -191,29 +191,6 @@ struct functor_trait<T_functor, false, true>   \
   typedef T_functor functor_type;              \
 };
 
-#ifndef SIGCXX_DISABLE_DEPRECATED
-/** Helper macro, if you want to mix user-defined and third party functors with libsigc++.
- *
- * If you want to mix functors not derived from sigc::functor_base with libsigc++,
- * and your compiler can deduce the result type of the functor with the C++11
- * keyword <tt>decltype</tt>, use this macro inside namespace sigc like so:
- * @code
- * namespace sigc {
- *   SIGC_FUNCTORS_DEDUCE_RESULT_TYPE_WITH_DECLTYPE
- * }
- * @endcode
- *
- * Functors with overloaded operator()() are not supported.
- *
- * @newin{2,2,11}
- *
- * @deprecated This macro does nothing. The test it activated in libsigc++
- *             versions before 2.6, is now unconditionally activated.
- *
- * @ingroup sigcfunctors
- */
-#define SIGC_FUNCTORS_DEDUCE_RESULT_TYPE_WITH_DECLTYPE // Empty
-#endif // SIGCXX_DISABLE_DEPRECATED
 
 #ifndef DOXYGEN_SHOULD_SKIP_THIS
 // detect the the functor version of non-functor types.