From d92fe05176230138be886f83e352065d1017bfe1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A9ter=20Kardos?= <kardospeter1994@hotmail.com>
Date: Thu, 17 Nov 2022 14:21:35 +0100
Subject: [PATCH 1/2] force qualified names for recursion

---
 include/gridtools/fn/unstructured.hpp | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/include/gridtools/fn/unstructured.hpp b/include/gridtools/fn/unstructured.hpp
index 049217a65..b175e4a5a 100644
--- a/include/gridtools/fn/unstructured.hpp
+++ b/include/gridtools/fn/unstructured.hpp
@@ -101,10 +101,13 @@ namespace gridtools::fn {
         template <class Tag, class Ptr, class Strides, class Domain, class Dim, class Offset, class... Offsets>
         GT_FUNCTION constexpr auto shift(
             iterator<Tag, Ptr, Strides, Domain> const &it, Dim, Offset offset, Offsets... offsets) {
-            if constexpr (has_key<decltype(it.m_domain.m_tables), Dim>()) {
-                return shift(horizontal_shift(it, Dim(), offset), offsets...);
+            if constexpr (sizeof...(offsets) == 0) {
+                return it;
+            }
+            else if constexpr (has_key<decltype(it.m_domain.m_tables), Dim>()) {
+                return unstructured_impl_::shift(horizontal_shift(it, Dim(), offset), offsets...);
             } else {
-                return shift(non_horizontal_shift(it, Dim(), offset), offsets...);
+                return unstructured_impl_::shift(non_horizontal_shift(it, Dim(), offset), offsets...);
             }
         }
         template <class Tag, class Ptr, class Strides, class Domain>

From f0bb2b3599a8fd7ca3e0a3a4d3003a2d175a308c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A9ter=20Kardos?= <kardospeter1994@hotmail.com>
Date: Thu, 17 Nov 2022 17:04:14 +0100
Subject: [PATCH 2/2] fixed logic

---
 include/gridtools/fn/unstructured.hpp | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/include/gridtools/fn/unstructured.hpp b/include/gridtools/fn/unstructured.hpp
index b175e4a5a..0de6a4edc 100644
--- a/include/gridtools/fn/unstructured.hpp
+++ b/include/gridtools/fn/unstructured.hpp
@@ -98,22 +98,20 @@ namespace gridtools::fn {
             return shifted;
         }
 
+        template <class Tag, class Ptr, class Strides, class Domain>
+        GT_FUNCTION constexpr auto shift(iterator<Tag, Ptr, Strides, Domain> const &it) {
+            return it;
+        }
+        
         template <class Tag, class Ptr, class Strides, class Domain, class Dim, class Offset, class... Offsets>
         GT_FUNCTION constexpr auto shift(
             iterator<Tag, Ptr, Strides, Domain> const &it, Dim, Offset offset, Offsets... offsets) {
-            if constexpr (sizeof...(offsets) == 0) {
-                return it;
-            }
-            else if constexpr (has_key<decltype(it.m_domain.m_tables), Dim>()) {
+            if constexpr (has_key<decltype(it.m_domain.m_tables), Dim>()) {
                 return unstructured_impl_::shift(horizontal_shift(it, Dim(), offset), offsets...);
             } else {
                 return unstructured_impl_::shift(non_horizontal_shift(it, Dim(), offset), offsets...);
             }
         }
-        template <class Tag, class Ptr, class Strides, class Domain>
-        GT_FUNCTION constexpr auto shift(iterator<Tag, Ptr, Strides, Domain> const &it) {
-            return it;
-        }
 
         template <class Domain>
         struct make_iterator {