diff --git a/src/ranges/single_range.h b/src/ranges/single_range.h
index a825531..40f6fea 100644
--- a/src/ranges/single_range.h
+++ b/src/ranges/single_range.h
@@ -64,8 +64,9 @@ namespace MultiArrayTools
 	std::string id();
 	void print(size_t offset);
 
-	template <class Expr>
-	auto ifor(Expr&& ex) const -> For<SingleIndex<U,TYPE>,Expr>;
+	template <class Expr, class... Ops>
+	auto ifor(std::tuple<to_size_t<Ops>...>&& ee, Expr&& ex) const
+	    -> For<SingleIndex<U,TYPE>,Expr,Ops...>;
     };
 
     template <typename U, SpaceType TYPE>
@@ -247,12 +248,12 @@ namespace MultiArrayTools
     }
 
     template <typename U, SpaceType TYPE>
-    template <class Expr>
-    auto SingleIndex<U,TYPE>::ifor(Expr&& ex) const
-	-> For<SingleIndex<U,TYPE>,Expr>
+    template <class Expr, class... Ops>
+    auto SingleIndex<U,TYPE>::ifor(std::tuple<to_size_t<Ops>...>&& ee, Expr&& ex) const
+	-> For<SingleIndex<U,TYPE>,Expr,Ops...>
     {
 	return For<SingleIndex<U,TYPE>,Expr>
-	    ( std::make_shared<SingleIndex<U,TYPE> >(*this), ex );
+	    ( std::make_shared<SingleIndex<U,TYPE> >(*this), ex, ee );
     }
 
     
diff --git a/src/xfor/for_utils.h b/src/xfor/for_utils.h
new file mode 100644
index 0000000..05f577d
--- /dev/null
+++ b/src/xfor/for_utils.h
@@ -0,0 +1,41 @@
+
+#ifndef __for_utils_h__
+#define __for_utils_h__
+
+#include "ranges/rheader.h"
+#include <array>
+#include <tuple>
+
+namespace MultiArrayHelper
+{
+    namespace {
+        template <class Op>
+        using to_size_t = size_t;
+    }
+    
+    template <size_t N>
+    struct XFPackNum
+    {
+	template <class IndexClass, class ExtTuple, class LastTuple, typename... Args>
+	static auto mkPos(const IndexClass& ind, const ExtTuple& et, const LastTuple& lt, const Args&... args)
+	    -> decltype(XFPackNum<N-1>::mkPos(et, lt, 0ul, args...))
+	{
+	    return XFPackNum<N-1>::mkPos(et, lt, std::get<N>(lt) + ind.pos() * std::get<N>(et), args...);
+	}
+    };
+
+    template <>
+    struct XFPackNum<0>
+    {
+	template <class IndexClass, class ExtTuple, class LastTuple, typename... Args>
+	static auto mkPos(const IndexClass& ind, const ExtTuple& et, const LastTuple& lt, const Args&... args)
+	    -> std::tuple<size_t,to_size_t<Args>...>
+	{
+	    return std::tuple<size_t,to_size_t<Args>...>(std::get<0>(lt) + ind.pos() * std::get<0>(et), args...);
+	}
+
+    };
+    
+} // end namespace MultiArrayHelper
+
+#endif
diff --git a/src/xfor/index_for_utils.h b/src/xfor/index_for_utils.h
deleted file mode 100644
index cc8145d..0000000
--- a/src/xfor/index_for_utils.h
+++ /dev/null
@@ -1,55 +0,0 @@
-
-#ifndef __index_for_utils_h__
-#define __index_for_utils_h__
-
-#include "ranges/rheader.h"
-#include "xfor.h"
-#include <array>
-#include <tuple>
-
-namespace MultiArrayHelper
-{
-    namespace {
-        template <class Op>
-        using to_size_t<Op> = size_t;
-    }
-    
-    template <size_t N>
-    struct XFPackNum
-    {
-	template <class Expr, class IndexClass, typename... Args>
-	static auto mkFor(const std::shared_ptr<IndexClass>& iPtr, const Args&... args)
-	    -> For<IndexClass,decltype(XFPackNum<N-1>::mkFor<Expr>(args...))>
-	{
-	    return For<IndexClass,decltype(XFPackNum<N-1>::mkFor<Expr>(args...))>(iPtr, args...);
-	}
-
-	template <class Expr, class IndexTuple, typename... Args>
-	static auto mkForTp(const IndexTuple& iTuple, const Args&... args)
-	    -> decltype(XFPackNum<N-1>::mkForTp(std::get<N>(iTuple), args...))
-	{
-	    return XFPackNum<N-1>::mkForTp(iTuple, std::get<N>(iTuple), args...)
-	}
-    };
-
-    template <>
-    struct XFPackNum<0>
-    {
-	template <class Expr, class IndexClass, typename... Args>
-	static auto mkFor(const std::shared_ptr<IndexClass>& iPtr, const Args&... args)
-	    -> For<IndexClass,Expr>
-	{
-	    return For<IndexClass,Expr>(iPtr, args...);
-	}
-
-	template <class Expr, class IndexTuple, typename... Args>
-	static auto mkForTp(const IndexTuple& iTuple, const Args&... args)
-	    -> decltype(XFPackNum<std::tuple_size<IndexTuple>::value-1>::mkFor( std::get<0>(iTuple), args... ))
-	{
-	    return XFPackNum<std::tuple_size<IndexTuple>::value-1>::mkFor( std::get<0>(iTuple), args... );
-	}
-    };
-    
-} // end namespace MultiArrayHelper
-
-#endif
diff --git a/src/xfor/xfor.h b/src/xfor/xfor.h
index 4499b06..1dd9099 100644
--- a/src/xfor/xfor.h
+++ b/src/xfor/xfor.h
@@ -5,13 +5,10 @@
 #include <cstdlib>
 #include <memory>
 #include <tuple>
+#include "xfor/for_utils.h"
 
 namespace MultiArrayHelper
 {
-    namespace {
-	template <class Op>
-	using to_size_t = size_t;
-    }
     
     template <class IndexClass, class Expr, class... Ops>
     class For
@@ -70,7 +67,7 @@ namespace MultiArrayHelper
 	const size_t max = ind.max();
 	for(ind = 0; ind.pos() != max; ++ind){
 	    const size_t mnpos = mlast * max + ind.pos();
-	    const std::tuple<to_size_t<Ops>...> npos( /* !!! fancy code !!! */ ); 
+	    const std::tuple<to_size_t<Ops>...> npos = std::move( XFPackNum<opNum-1>::mkPos(ind, mExt, last) );
 	    mExpr(mnpos, npos);
 	}
     }