Fusion: added nview and friends

[SVN r56376]
2009-09-25 00:20:03 +00:00
parent b16d42a31b
commit 43645b3764
16 changed files with 721 additions and 0 deletions
--- a/include/boost/fusion/view/nview/nview.hpp
+++ b/include/boost/fusion/view/nview/nview.hpp
@ -0,0 +1,79 @@
+/*=============================================================================
+    Copyright (c) 2009 Hartmut Kaiser
+
+    Distributed under the Boost Software License, Version 1.0. (See accompanying 
+    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+==============================================================================*/
+
+#if !defined(BOOST_FUSION_NVIEW_SEP_23_2009_0948PM)
+#define BOOST_FUSION_NVIEW_SEP_23_2009_0948PM
+
+#include <boost/mpl/size.hpp>
+#include <boost/mpl/if.hpp>
+#include <boost/mpl/vector_c.hpp>
+#include <boost/utility/result_of.hpp>
+
+#include <boost/type_traits/remove_reference.hpp>
+
+#include <boost/fusion/support/is_view.hpp>
+#include <boost/fusion/support/category_of.hpp>
+#include <boost/fusion/support/sequence_base.hpp>
+#include <boost/fusion/container/vector.hpp>
+#include <boost/fusion/view/transform_view.hpp>
+
+namespace boost { namespace fusion
+{
+    namespace detail
+    {
+        struct addref
+        {
+            template<typename Sig>
+            struct result;
+
+            template<typename U>
+            struct result<addref(U)> : boost::add_reference<U> {};
+
+            template <typename T>
+            typename boost::result_of<addref(T)>::type 
+            operator()(T& x) const
+            {
+                return x;
+            }
+        };
+    }
+
+    struct nview_tag;
+    struct random_access_traversal_tag;
+    struct fusion_sequence_tag;
+
+    template<typename Sequence, typename Indicies>
+    struct nview
+      : sequence_base<nview<Sequence, Indicies> >
+    {
+        typedef nview_tag fusion_tag;
+        typedef fusion_sequence_tag tag; // this gets picked up by MPL
+        typedef random_access_traversal_tag category;
+
+        typedef mpl::true_ is_view;
+        typedef Indicies index_type;
+        typedef typename mpl::size<Indicies>::type size;
+
+        typedef transform_view<Sequence, detail::addref> transform_view_type;
+        typedef typename result_of::as_vector<transform_view_type>::type 
+            sequence_type;
+
+        explicit nview(Sequence& val)
+          : seq(as_vector(transform_view_type(val, detail::addref()))) 
+        {}
+
+        sequence_type seq;
+    };
+
+}}
+
+// define the nview() generator functions
+#include <boost/fusion/view/nview/detail/nview_impl.hpp>
+
+#endif
+
+