Move definition of index_style_t from iterator_traits.hpp into suite_utils.hpp

[SVN r20525]

include/boost/python/suite/indexing/suite_utils.hpp

@@ -1,5 +1,3 @@
-// -*- mode:c++ -*-
-//
 // Header file suite_utils.hpp
 //
 // Shared utilities for the indexing suite.
@@ -23,6 +21,24 @@
 #include <boost/type_traits.hpp>
 
 namespace boost { namespace python { namespace indexing {
+#if !BOOST_MSVC
+  enum index_style_t {
+    index_style_none         // No random access (iteration only)
+    , index_style_nonlinear  // Random access by key (no slicing)
+    , index_style_linear     // Random access by integer index (allows slicing)
+  };
+#else
+  // MSVC seems to have problems with static member variable constants
+  // of enumerated types, where it doesn't believe that an expression
+  // like (traits::index_style == index_style_linear) is a
+  // compile-time constant. However, the problem doesn't exist for
+  // int.
+  typedef int index_style_t;
+  index_style_t const index_style_none = 0;
+  index_style_t const index_style_nonlinear = 1;
+  index_style_t const index_style_linear = 2;
+#endif
+
   template<typename T>
   class is_mutable_ref
   {