From 7d10c787386c8b789d219392028ad38d36d5f82a Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Tue, 19 Feb 2019 10:31:56 +0100
Subject: [PATCH] bug #1046: add unit tests for correct propagation of
 alignment through std::alignment_of

---
 test/dense_storage.cpp | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/test/dense_storage.cpp b/test/dense_storage.cpp
index 1150ec52b..7fa25859d 100644
--- a/test/dense_storage.cpp
+++ b/test/dense_storage.cpp
@@ -52,6 +52,32 @@ void dense_storage_assignment()
     VERIFY_IS_EQUAL(raw_reference[i], raw_copied_reference[i]);
 }
 
+template<typename T, int Size, std::size_t Alignment>
+void dense_storage_alignment()
+{
+  #if EIGEN_HAS_ALIGNAS
+  
+  struct alignas(Alignment) Empty1 {};
+  VERIFY_IS_EQUAL(std::alignment_of<Empty1>::value, Alignment);
+
+  struct EIGEN_ALIGN_TO_BOUNDARY(Alignment) Empty2 {};
+  VERIFY_IS_EQUAL(std::alignment_of<Empty2>::value, Alignment);
+
+  struct Nested1 { EIGEN_ALIGN_TO_BOUNDARY(Alignment) T data[Size]; };
+  VERIFY_IS_EQUAL(std::alignment_of<Nested1>::value, Alignment);
+
+  VERIFY_IS_EQUAL( (std::alignment_of<internal::plain_array<T,Size,AutoAlign,Alignment> >::value), Alignment);
+
+  const std::size_t default_alignment = internal::compute_default_alignment<T,Size>::value;
+
+  VERIFY_IS_EQUAL( (std::alignment_of<DenseStorage<T,Size,1,1,AutoAlign> >::value), default_alignment);
+  VERIFY_IS_EQUAL( (std::alignment_of<Matrix<T,Size,1,AutoAlign> >::value), default_alignment);
+  struct Nested2 { Matrix<T,Size,1,AutoAlign> mat; };
+  VERIFY_IS_EQUAL(std::alignment_of<Nested2>::value, default_alignment);
+
+  #endif
+}
+
 EIGEN_DECLARE_TEST(dense_storage)
 {
   dense_storage_copy<int,Dynamic,Dynamic>();  
@@ -72,5 +98,10 @@ EIGEN_DECLARE_TEST(dense_storage)
   dense_storage_assignment<float,Dynamic,Dynamic>();
   dense_storage_assignment<float,Dynamic,3>();
   dense_storage_assignment<float,4,Dynamic>();  
-  dense_storage_assignment<float,4,3>();  
+  dense_storage_assignment<float,4,3>(); 
+
+  dense_storage_alignment<float,16,8>();
+  dense_storage_alignment<float,16,16>();
+  dense_storage_alignment<float,16,32>();
+  dense_storage_alignment<float,16,64>();
 }