From dfa6a16dcbfe1b98e1890b8ea38f9c85a2346536 Mon Sep 17 00:00:00 2001
From: Joel Falcou <jfalcou@codereckons.com>
Date: Mon, 13 Oct 2025 19:48:55 +0200
Subject: [PATCH] Fix ref<> behavior on storage order

See merge request oss/rotgen!39
---
 include/rotgen/container/ref.hpp | 20 +++++++-------------
 1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/include/rotgen/container/ref.hpp b/include/rotgen/container/ref.hpp
index 53503f3..5c4b409 100644
--- a/include/rotgen/container/ref.hpp
+++ b/include/rotgen/container/ref.hpp
@@ -80,27 +80,22 @@ namespace rotgen
     template<std::same_as<value_type> S, int R, int C, int O, int MR, int MC>
     ref(matrix<S, R, C, O, MR, MC>& m)
       : parent(m.data(), m.rows(), m.cols(), strides(m))
-    {
-      static_assert((O & 1) == storage_order, "ref: Incompatible storage layout");
-    }
+    {}
 
     template<typename Ref, int R, int C, bool I>
+    requires(std::same_as<value_type, typename Ref::value_type> && (Ref::storage_order & 1) == storage_order)
     ref(block<Ref,R,C,I>&& b) : parent(b.data(), b.rows(), b.cols(), stride_type{b.outerStride(),b.innerStride()})
-    {
-      static_assert((Ref::storage_order & 1) == storage_order, "ref: Incompatible storage layout");
-    }
+    {}
 
     template<typename Ref, int R, int C, bool I>
+    requires(std::same_as<value_type, typename Ref::value_type> && (Ref::storage_order & 1) == storage_order)
     ref(block<Ref,R,C,I>& b) : parent(b.data(), b.rows(), b.cols(), stride_type{b.outerStride(),b.innerStride()})
-    {
-      static_assert((Ref::storage_order & 1) == storage_order, "ref: Incompatible storage layout");
-    }
+    {}
 
     template<typename Ref, int O, typename S>
+    requires(std::same_as<value_type, typename Ref::value_type> && (Ref::storage_order & 1) == storage_order)
     ref(map<Ref,O,S>& b) : parent(b.data(), b.rows(), b.cols(), stride_type{b.outerStride(),b.innerStride()})
-    {
-      static_assert((Ref::storage_order & 1) == storage_order, "ref: Incompatible storage layout");
-    }
+    {}
 
     template<typename TT, int OO, typename SS>
     ref ( ref<TT,OO,SS>& b )
@@ -180,7 +175,6 @@ namespace rotgen
 
     template<std::same_as<value_type> S, int R, int C, int O, int MR, int MC>
     ref(matrix<S, R, C, O, MR, MC> const& m)
-    requires((O & 1) == storage_order)
       : parent(m.data(), m.rows(), m.cols(), strides(m))
     {}