add 'zip_view'

[SVN r16419]

include/boost/mpl/zip_view.hpp

@@ -0,0 +1,66 @@
+//-----------------------------------------------------------------------------
+// boost mpl/zip_view.hpp header file
+// See http://www.boost.org for updates, documentation, and revision history.
+//-----------------------------------------------------------------------------
+//
+// Copyright (c) 2000-02
+// David Abrahams, Aleksey Gurtovoy
+//
+// Permission to use, copy, modify, distribute and sell this software
+// and its documentation for any purpose is hereby granted without fee, 
+// provided that the above copyright notice appears in all copies and 
+// that both the copyright notice and this permission notice appear in 
+// supporting documentation. No representations are made about the 
+// suitability of this software for any purpose. It is provided "as is" 
+// without express or implied warranty.
+
+#ifndef BOOST_MPL_ZIP_VIEW_HPP_INCLUDED
+#define BOOST_MPL_ZIP_VIEW_HPP_INCLUDED
+
+#include "boost/mpl/transform.hpp"
+#include "boost/mpl/begin_end.hpp"
+#include "boost/mpl/iterator_tag.hpp"
+#include "boost/mpl/next.hpp"
+#include "boost/mpl/lambda.hpp"
+#include "boost/mpl/apply.hpp"
+#include "boost/mpl/aux_/void_spec.hpp"
+
+namespace boost { namespace mpl {
+
+template< typename IteratorSeq >
+struct zip_iterator
+{
+    typedef input_iter_tag_ category;
+    typedef typename transform<
+          IteratorSeq
+        , apply0<_1>
+        >::type type;
+
+    typedef zip_iterator<
+          typename transform<
+                IteratorSeq
+              , next<_1>
+            >::type
+        > next;
+};
+
+template<
+      typename BOOST_MPL_AUX_VOID_SPEC_PARAM(Sequences)
+    >
+struct zip_view
+{
+ private:    
+    typedef typename transform< Sequences, begin<_1> >::type first_ones_;
+    typedef typename transform< Sequences, end<_1> >::type last_ones_;
+    
+ public:
+    typedef nested_begin_end_tag tag;
+    typedef zip_iterator<first_ones_> begin;
+    typedef zip_iterator<last_ones_> end;
+};
+
+BOOST_MPL_AUX_VOID_SPEC(1, zip_view)
+
+}} // namespace boost::mpl
+
+#endif // BOOST_MPL_ZIP_VIEW_HPP_INCLUDED

test/zip_view.cpp

@@ -0,0 +1,60 @@
+//-----------------------------------------------------------------------------
+// boost mpl/test/zip_view.cpp source file
+// See http://www.boost.org for updates, documentation, and revision history.
+//-----------------------------------------------------------------------------
+//
+// Copyright (c) 2002
+// Aleksey Gurtovoy
+//
+// Permission to use, copy, modify, distribute and sell this software
+// and its documentation for any purpose is hereby granted without fee, 
+// provided that the above copyright notice appears in all copies and 
+// that both the copyright notice and this permission notice appear in 
+// supporting documentation. No representations are made about the 
+// suitability of this software for any purpose. It is provided "as is" 
+// without express or implied warranty.
+
+#include "boost/mpl/zip_view.hpp"
+#include "boost/mpl/transform_view.hpp"
+#include "boost/mpl/filter_view.hpp"
+#include "boost/mpl/range_c.hpp"
+#include "boost/mpl/list.hpp"
+#include "boost/mpl/at.hpp"
+#include "boost/mpl/equal.hpp"
+#include "boost/mpl/comparison/equal_to.hpp"
+#include "boost/mpl/math/is_even.hpp"
+#include "boost/static_assert.hpp"
+
+using namespace boost::mpl;
+
+template< typename BinaryOp >
+struct apply_two_args_seq
+{
+    template< typename Args > struct apply
+    {
+        typedef typename apply2<
+              BinaryOp
+            , typename at_c<Args,0>::type
+            , typename at_c<Args,1>::type
+            >::type type;
+    };
+};
+
+int main()
+{
+    typedef range_c<int,0,10> s1;
+    typedef range_c<int,10,20> s2;
+
+    typedef transform_view<
+          zip_view< list<s1,s2> >
+        , apply_two_args_seq< plus<> >
+        > result;
+
+    BOOST_STATIC_ASSERT((equal< 
+          result
+        , filter_view< range_c<int,10,30>, math::is_even<_> >
+        , equal_to<_,_>
+        >::type::value));
+
+    return 0;
+}