[libsigc++2/variadic] signal_emit: Reorder the typedefs to fix the build.

[Murray Cumming <murrayc src gnome org>]

commit fda09a60e45e0db40ac2949397c84d34a39154d9
Author: Murray Cumming <murrayc murrayc com>
Date:   Fri Jan 15 23:05:29 2016 +0100

    signal_emit: Reorder the typedefs to fix the build.

 sigc++/signal.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/sigc++/signal.h b/sigc++/signal.h
index 452285d..f25122c 100644
--- a/sigc++/signal.h
+++ b/sigc++/signal.h
@@ -614,11 +614,11 @@ template <class T_return, class T_accumulator, class... T_arg>
 struct signal_emit
 {
   typedef signal_emit<T_return, T_accumulator, T_arg...> self_type;
-  typedef decltype(std::declval<T_accumulator>()(slot_iterator_buf_type(), slot_iterator_buf_type())) 
result_type;
   typedef slot<T_return, T_arg...> slot_type;
   typedef internal::slot_iterator_buf<self_type, T_return> slot_iterator_buf_type;
   typedef internal::slot_reverse_iterator_buf<self_type, T_return> slot_reverse_iterator_buf_type;
   typedef signal_impl::const_iterator_type iterator_type;
+  typedef decltype(std::declval<T_accumulator>()(slot_iterator_buf_type(), slot_iterator_buf_type())) 
result_type;
 
   /** Instantiates the class.
    * The parameters are stored in member variables. operator()() passes