Add constraint for layout_left|right|stride::stride(), and add test

Addresses kokkos#201
youyu3 · Feb 3, 2023 · b421aa5 · b421aa5
1 parent 0a1ce8c
commit b421aa5
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Showing 7 changed files with 86 additions and 7 deletions.
diff --git a/include/experimental/__p0009_bits/layout_left.hpp b/include/experimental/__p0009_bits/layout_left.hpp
@@ -176,6 +176,12 @@ class layout_left::mapping {
     MDSPAN_INLINE_FUNCTION constexpr bool is_exhaustive() const noexcept { return true; }
     MDSPAN_INLINE_FUNCTION constexpr bool is_strided() const noexcept { return true; }
 
+    MDSPAN_TEMPLATE_REQUIRES(
+      class E = Extents,
+      /* requires */ (
+        E::rank() > 0
+      )
+    )
     MDSPAN_INLINE_FUNCTION
     constexpr index_type stride(rank_type i) const noexcept {
       index_type value = 1;

diff --git a/include/experimental/__p0009_bits/layout_right.hpp b/include/experimental/__p0009_bits/layout_right.hpp
@@ -178,6 +178,12 @@ class layout_right::mapping {
     MDSPAN_INLINE_FUNCTION constexpr bool is_exhaustive() const noexcept { return true; }
     MDSPAN_INLINE_FUNCTION constexpr bool is_strided() const noexcept { return true; }
 
+    MDSPAN_TEMPLATE_REQUIRES(
+      class E = Extents,
+      /* requires */ (
+        E::rank() > 0
+      )
+    )
     MDSPAN_INLINE_FUNCTION
     constexpr index_type stride(rank_type i) const noexcept {
       index_type value = 1;

diff --git a/include/experimental/__p0009_bits/layout_stride.hpp b/include/experimental/__p0009_bits/layout_stride.hpp
@@ -431,6 +431,12 @@ struct layout_stride {
     MDSPAN_INLINE_FUNCTION static constexpr bool is_strided() noexcept { return true; }
 
 
+    MDSPAN_TEMPLATE_REQUIRES(
+      class E = Extents,
+      /* requires */ (
+        E::rank() > 0
+      )
+    )
     MDSPAN_INLINE_FUNCTION
     constexpr index_type stride(rank_type r) const noexcept {
       return __strides_storage()[r];

diff --git a/tests/test_exhaustive_layouts.cpp b/tests/test_exhaustive_layouts.cpp
@@ -391,9 +391,11 @@ TYPED_TEST(TestLayoutConversion, implicit_conversion) {
   #endif
     map1 = typename TestFixture::map_1_t(map2);
 
-  for(size_t r=0; r != this->exts1.rank(); ++r) {
-    ASSERT_EQ(map1.extents().extent(r), map2.extents().extent(r));
-    ASSERT_EQ(map1.stride(r), map2.stride(r));
+  if constexpr (this->exts1.rank() > 0) {
+    for(size_t r=0; r != this->exts1.rank(); ++r) {
+      ASSERT_EQ(map1.extents().extent(r), map2.extents().extent(r));
+      ASSERT_EQ(map1.stride(r), map2.stride(r));
+    }
   }
 }
 
diff --git a/tests/test_layout_ctors.cpp b/tests/test_layout_ctors.cpp
@@ -239,3 +239,35 @@ TEST(TestLayoutRightCTAD, test_layout_right_ctad) {
   ASSERT_TRUE(m.is_exhaustive());
 }
 #endif
+
+template< class T, class RankType, class = void >
+struct is_stride_avail : std::false_type {};
+
+template< class T, class RankType >
+struct is_stride_avail< T
+                      , RankType
+                      , std::enable_if_t< std::is_same< decltype( std::declval<T>().stride( std::declval<RankType>() ) )
+                                                      , typename T::index_type
+                                                      >::value
+                                        >
+                      > : std::true_type {};
+
+TEST(TestLayoutLeftStrideConstraint, test_layout_left_stride_constraint) {
+  stdex::extents<int,16> ext1d{};
+  stdex::layout_left::mapping m1d{ext1d};
+  ASSERT_TRUE ((is_stride_avail< decltype(m1d), int >::value));
+
+  stdex::extents<int> ext0d{};
+  stdex::layout_left::mapping m0d{ext0d};
+  ASSERT_FALSE((is_stride_avail< decltype(m0d), int >::value));
+}
+
+TEST(TestLayoutRightStrideConstraint, test_layout_right_stride_constraint) {
+  stdex::extents<int,16> ext1d{};
+  stdex::layout_right::mapping m1d{ext1d};
+  ASSERT_TRUE ((is_stride_avail< decltype(m1d), int >::value));
+
+  stdex::extents<int> ext0d{};
+  stdex::layout_right::mapping m0d{ext0d};
+  ASSERT_FALSE((is_stride_avail< decltype(m0d), int >::value));
+}
diff --git a/tests/test_layout_stride.cpp b/tests/test_layout_stride.cpp
@@ -206,3 +206,24 @@ TEST(TestLayoutStrideCTAD, test_ctad) {
 }
 #endif
 
+template< class T, class RankType, class = void >
+struct is_stride_avail : std::false_type {};
+
+template< class T, class RankType >
+struct is_stride_avail< T
+                      , RankType
+                      , std::enable_if_t< std::is_same< decltype( std::declval<T>().stride( std::declval<RankType>() ) )
+                                                      , typename T::index_type
+                                                      >::value
+                                        >
+                      > : std::true_type {};
+
+TEST(TestLayoutStrideStrideConstraint, test_layout_stride_stride_constraint) {
+  stdex::extents<int,16> ext1d{};
+  stdex::layout_stride::mapping m1d{ext1d, std::array<int,1>{1}};
+  ASSERT_TRUE ((is_stride_avail< decltype(m1d), int >::value));
+
+  stdex::extents<int> ext0d{};
+  stdex::layout_stride::mapping m0d{ext0d, std::array<int,0>{}};
+  ASSERT_FALSE((is_stride_avail< decltype(m0d), int >::value));
+}
diff --git a/tests/test_mdarray_ctors.cpp b/tests/test_mdarray_ctors.cpp
@@ -141,17 +141,23 @@ void check_correctness(MDA& m, size_t rank, size_t rank_dynamic,
                        bool exhaustive) {
   ASSERT_EQ(m.rank(), rank);
   ASSERT_EQ(m.rank_dynamic(), rank_dynamic);
-  if(rank>0) {
+  if (rank>0) {
     ASSERT_EQ(m.extent(0), extent_0);
-    ASSERT_EQ(m.stride(0), stride_0);
+    if constexpr (m.rank()>0) {
+      ASSERT_EQ(m.stride(0), stride_0);
+    }
   }
   if(rank>1) {
     ASSERT_EQ(m.extent(1), extent_1);
-    ASSERT_EQ(m.stride(1), stride_1);
+    if constexpr (m.rank()>0) {
+      ASSERT_EQ(m.stride(1), stride_1);
+    }
   }
   if(rank>2) {
     ASSERT_EQ(m.extent(2), extent_2);
-    ASSERT_EQ(m.stride(2), stride_2);
+    if constexpr (m.rank()>0) {
+      ASSERT_EQ(m.stride(2), stride_2);
+    }
   }
   if(ptr_matches)
     ASSERT_EQ(m.data(),ptr);