microsoft · StephanTLavavej · Jul 3, 2023 · Jun 21, 2023 · Jun 21, 2023 · Jun 21, 2023
diff --git a/stl/inc/mdspan b/stl/inc/mdspan
diff --git a/tests/std/include/test_mdspan_support.hpp b/tests/std/include/test_mdspan_support.hpp
@@ -267,14 +267,13 @@ struct MappingProperties {
 template <class Mapping>
     requires (!details::PermissiveTest<Mapping>::test())
 MappingProperties<Mapping> get_mapping_properties(const Mapping& mapping) {
-    using IndexType          = typename Mapping::index_type;
-    constexpr IndexType zero = 0;
-    constexpr auto rank      = Mapping::extents_type::rank();
+    using IndexType     = typename Mapping::index_type;
+    constexpr auto rank = Mapping::extents_type::rank();
     constexpr std::make_index_sequence<rank> rank_indices;
 
     auto get_extent       = [&](size_t i) { return mapping.extents().extent(i); };
     auto multidim_indices = [&]<size_t... Indices>(std::index_sequence<Indices...>) {
-        return std::views::cartesian_product(std::views::iota(zero, get_extent(Indices))...);
+        return std::views::cartesian_product(std::views::iota(IndexType{0}, get_extent(Indices))...);
     }(rank_indices);
 
     auto map_index      = [&](const auto& tpl) { return std::apply([&](auto... i) { return mapping(i...); }, tpl); };
@@ -284,19 +283,18 @@ MappingProperties<Mapping> get_mapping_properties(const Mapping& mapping) {
     MappingProperties<Mapping> props{};
 
     // Find required span size (N4950 [mdspan.layout.reqmts]/12)
-    if (std::ranges::contains(std::views::iota(0u, rank) | std::views::transform(get_extent), zero)) {
+    if (std::ranges::contains(std::views::iota(0u, rank) | std::views::transform(get_extent), IndexType{0})) {
         props.req_span_size = 0;
     } else {
         props.req_span_size = static_cast<IndexType>(1 + mapped_indices.back());
     }
 
     // Is mapping unique? (N4950 [mdspan.layout.reqmts]/14)
-    props.uniqueness = !std::ranges::contains(std::views::pairwise_transform(mapped_indices, std::minus{}), zero);
+    props.uniqueness = std::ranges::adjacent_find(mapped_indices) == mapped_indices.end();
 
-    { // Is mapping exhaustive? (N4950 [mdspan.layout.reqmts]/16)
-        const auto diffs     = std::views::pairwise_transform(mapped_indices, [](auto x, auto y) { return y - x; });
-        props.exhaustiveness = std::ranges::find_if_not(diffs, [](auto x) { return x == 1; }) == diffs.end();
-    }
+    // Is mapping exhaustive? (N4950 [mdspan.layout.reqmts]/16)
+    props.exhaustiveness =
+        std::ranges::adjacent_find(mapped_indices, [](auto x, auto y) { return y - x > 1; }) == mapped_indices.end();
 
     { // Is mapping strided? (N4950 [mdspan.layout.reqmts]/18)
         props.strideness = true; // assumption

diff --git a/tests/std/test.lst b/tests/std/test.lst
@@ -246,6 +246,7 @@ tests\P0009R18_mdspan_layout_right_death
 tests\P0009R18_mdspan_layout_stride
 tests\P0009R18_mdspan_layout_stride_death
 tests\P0009R18_mdspan_mdspan
+tests\P0009R18_mdspan_mdspan_death
 tests\P0019R8_atomic_ref
 tests\P0024R2_parallel_algorithms_adjacent_difference
 tests\P0024R2_parallel_algorithms_adjacent_find

diff --git a/tests/std/tests/P0009R18_mdspan_extents_death/test.cpp b/tests/std/tests/P0009R18_mdspan_extents_death/test.cpp
@@ -54,6 +54,13 @@ void test_construction_from_pack_with_unrepresentable_as_index_type_values_2() {
     [[maybe_unused]] extents<unsigned char, 1, dynamic_extent> e{ConvertibleToInt<unsigned char>{.val = 1}, 256};
 }
 
+void test_construction_from_pack_with_unrepresentable_as_index_type_values_3() {
+    static_assert(signed_integral<char>, "char is not signed integral");
+    // Either sizeof...(exts) must be equal to 0 or each element of exts must be nonnegative and must be representable
+    // as value of type index_type
+    [[maybe_unused]] extents<signed char, 1, dynamic_extent> e{static_cast<char>(-1)};
+}
+
 void test_construction_from_span_with_invalid_values() {
     int vals[] = {1, 2};
     span s{vals};
@@ -93,6 +100,7 @@ int main(int argc, char* argv[]) {
         test_construction_from_pack_with_invalid_values,
         test_construction_from_pack_with_unrepresentable_as_index_type_values_1,
         test_construction_from_pack_with_unrepresentable_as_index_type_values_2,
+        test_construction_from_pack_with_unrepresentable_as_index_type_values_3,
         test_construction_from_span_with_invalid_values,
         test_construction_from_span_with_unrepresentable_as_index_type_values,
         test_construction_from_array_with_invalid_values,

diff --git a/tests/std/tests/P0009R18_mdspan_layout_left/test.cpp b/tests/std/tests/P0009R18_mdspan_layout_left/test.cpp
@@ -161,7 +161,7 @@ constexpr void check_members(const extents<IndexType, Extents...>& ext, index_se
 
 void check_mapping_properties() {
     if constexpr (!is_permissive) {
-        auto check = []([[maybe_unused]] const auto& mapping) {
+        auto check = [](const auto& mapping) {
             const auto props = get_mapping_properties(mapping);
             assert(props.req_span_size == mapping.required_span_size());
             assert(props.uniqueness);
@@ -465,6 +465,9 @@ constexpr void check_correctness() {
 #endif // ^^^ !defined(__cpp_multidimensional_subscript) ^^^
     }
 
+#ifdef __clang__
+    if (!is_constant_evaluated()) // FIXME clang hits constexpr limit here
+#endif
     { // 2x3x2x3 tensor
         const array values{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,
             26, 27, 28, 29, 30, 31, 32, 33, 34, 35};
@@ -491,10 +494,7 @@ constexpr void check_correctness() {
 }
 
 constexpr bool test() {
-    check_members_with_various_extents(
-        []<class IndexType, size_t... Extents>(const extents<IndexType, Extents...>& ext) {
-            check_members(ext, make_index_sequence<sizeof...(Extents)>{});
-        });
+    check_members_with_various_extents([]<class E>(const E& e) { check_members(e, make_index_sequence<E::rank()>{}); });
     if (!is_constant_evaluated()) { // too heavy for compile time
         check_mapping_properties();
     }

diff --git a/tests/std/tests/P0009R18_mdspan_layout_left_death/test.cpp b/tests/std/tests/P0009R18_mdspan_layout_left_death/test.cpp
@@ -1,6 +1,8 @@
 // Copyright (c) Microsoft Corporation.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
+#define _CONTAINER_DEBUG_LEVEL 1
+
 #include <array>
 #include <cstddef>
 #include <mdspan>
@@ -10,7 +12,17 @@
 
 using namespace std;
 
-// TRANSITION, Test Construction From extents_type
+void test_construction_from_extents_type_with_signed_index_type() {
+    using Ext = dextents<signed char, 3>;
+    // The size of the multidimensional index space e must be representable as a value of type index_type
+    [[maybe_unused]] layout_left::mapping<Ext> m{Ext{5, 4, 7}};
+}
+
+void test_construction_from_extents_type_with_unsigned_index_type() {
+    using Ext = dextents<unsigned char, 3>;
+    // The size of the multidimensional index space e must be representable as a value of type index_type
+    [[maybe_unused]] layout_left::mapping<Ext> m{Ext{5, 10, 6}};
+}
 
 void test_construction_from_other_left_mapping() {
     layout_left::mapping<dextents<int, 1>> m1{dextents<int, 1>{256}};
@@ -26,7 +38,7 @@ void test_construction_from_other_right_mapping() {
 
 void test_construction_from_other_stride_mapping_1() {
     using Ext = extents<int, 2, 4>;
-    layout_stride::mapping<Ext> m1{Ext{}, array{1, 1}};
+    layout_stride::mapping<Ext> m1{Ext{}, array{4, 1}};
     // For all r in the range [0, extents_type::rank()), other.stride(r) must be equal to
     // extents().fwd-prod-of-extents(r)
     layout_left::mapping<Ext> m2{m1};
@@ -53,7 +65,8 @@ void test_stride_function() {
 int main(int argc, char* argv[]) {
     std_testing::death_test_executive exec;
     exec.add_death_tests({
-        // TRANSITION Construction From extents_type
+        test_construction_from_extents_type_with_signed_index_type,
+        test_construction_from_extents_type_with_unsigned_index_type,
         test_construction_from_other_left_mapping,
         test_construction_from_other_right_mapping,
         test_construction_from_other_stride_mapping_1,

diff --git a/tests/std/tests/P0009R18_mdspan_layout_right/test.cpp b/tests/std/tests/P0009R18_mdspan_layout_right/test.cpp
@@ -33,6 +33,9 @@ constexpr void check_members(const extents<IndexType, Extents...>& ext, index_se
     static_assert(same_as<typename Mapping::rank_type, typename Ext::rank_type>);
     static_assert(same_as<typename Mapping::layout_type, layout_right>);
 
+#ifdef __clang__
+    if (!is_constant_evaluated()) // FIXME clang hits constexpr limit here
+#endif
     { // Check default and copy constructor
         const Mapping m;
         Mapping cpy = m;
@@ -160,7 +163,7 @@ constexpr void check_members(const extents<IndexType, Extents...>& ext, index_se
 
 void check_mapping_properties() {
     if constexpr (!is_permissive) {
-        auto check = []([[maybe_unused]] const auto& mapping) {
+        auto check = [](const auto& mapping) {
             const auto props = get_mapping_properties(mapping);
             assert(props.req_span_size == mapping.required_span_size());
             assert(props.uniqueness);
@@ -514,10 +517,7 @@ constexpr void check_correctness() {
 }
 
 constexpr bool test() {
-    check_members_with_various_extents(
-        []<class IndexType, size_t... Extents>(const extents<IndexType, Extents...>& ext) {
-            check_members(ext, make_index_sequence<sizeof...(Extents)>{});
-        });
+    check_members_with_various_extents([]<class E>(const E& e) { check_members(e, make_index_sequence<E::rank()>{}); });
     if (!is_constant_evaluated()) { // too heavy for compile time
         check_mapping_properties();
     }

diff --git a/tests/std/tests/P0009R18_mdspan_layout_right_death/test.cpp b/tests/std/tests/P0009R18_mdspan_layout_right_death/test.cpp
@@ -1,6 +1,8 @@
 // Copyright (c) Microsoft Corporation.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
+#define _CONTAINER_DEBUG_LEVEL 1
+
 #include <array>
 #include <cstddef>
 #include <mdspan>
@@ -10,7 +12,17 @@
 
 using namespace std;
 
-// TRANSITION, Test Construction From extents_type
+void test_construction_from_extents_type_with_signed_index_type() {
+    using Ext = dextents<signed char, 3>;
+    // The size of the multidimensional index space e must be representable as a value of type index_type
+    [[maybe_unused]] layout_right::mapping<Ext> m{Ext{5, 4, 7}};
+}
+
+void test_construction_from_extents_type_with_unsigned_index_type() {
+    using Ext = dextents<unsigned char, 3>;
+    // The size of the multidimensional index space e must be representable as a value of type index_type
+    [[maybe_unused]] layout_right::mapping<Ext> m{Ext{5, 10, 6}};
+}
 
 void test_construction_from_other_right_mapping() {
     layout_right::mapping<dextents<int, 1>> m1{dextents<int, 1>{256}};
@@ -26,7 +38,7 @@ void test_construction_from_other_left_mapping() {
 
 void test_construction_from_other_stride_mapping_1() {
     using Ext = extents<int, 2, 4>;
-    layout_stride::mapping<Ext> m1{Ext{}, array{3, 1}};
+    layout_stride::mapping<Ext> m1{Ext{}, array{1, 2}};
     // For all r in the range [0, extents_type::rank()), other.stride(r) must be equal to
     // extents().rev-prod-of-extents(r)
     layout_right::mapping<Ext> m2{m1};
@@ -53,7 +65,8 @@ void test_stride_function() {
 int main(int argc, char* argv[]) {
     std_testing::death_test_executive exec;
     exec.add_death_tests({
-        // TRANSITION Construction From extents_type
+        test_construction_from_extents_type_with_signed_index_type,
+        test_construction_from_extents_type_with_unsigned_index_type,
         test_construction_from_other_right_mapping,
         test_construction_from_other_left_mapping,
         test_construction_from_other_stride_mapping_1,

diff --git a/tests/std/tests/P0009R18_mdspan_layout_stride_death/test.cpp b/tests/std/tests/P0009R18_mdspan_layout_stride_death/test.cpp
@@ -1,24 +1,49 @@
 // Copyright (c) Microsoft Corporation.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
+#define _CONTAINER_DEBUG_LEVEL 1
+
 #include <array>
 #include <cstddef>
 #include <mdspan>
 #include <span>
 
 #include <test_death.hpp>
+#include <test_mdspan_support.hpp>
 
 using namespace std;
 
-void test_construction_from_extents_and_array() {
+void test_default_construction() {
+    using Ext = extents<signed char, dynamic_extent, 4, 5, 7>;
+    // Value of layout_right::mapping<extents_type>().required_span_size() must be
+    // representable as a value of type index_type
+    [[maybe_unused]] layout_stride::mapping<Ext> m{}; // NB: strides are [140, 35, 7, 1]
+}
+
+void test_construction_from_extents_and_array_1() {
     // Value of s[i] must be greater than 0 for all i in the range [0, rank_)
     [[maybe_unused]] layout_stride::mapping<dextents<int, 1>> m1{extents<int, 1>{}, array<int, 1>{-1}};
 }
 
-void test_construction_from_extents_and_span() {
+void test_construction_from_extents_and_array_2() {
+    using Ext = extents<signed char, 120>;
+    // REQUIRED-SPAN-SIZE(e, s) must be representable as a value of type index_type
+    [[maybe_unused]] layout_stride::mapping<Ext> m{Ext{}, array<int, 1>{2}};
+}
+
+
+void test_construction_from_extents_and_span_1() {
     array<int, 1> s{-1};
     // Value of s[i] must be greater than 0 for all i in the range [0, rank_)
-    [[maybe_unused]] layout_stride::mapping<dextents<int, 1>> m1{extents<int, 1>{}, span{s}};
+    [[maybe_unused]] layout_stride::mapping<dextents<int, 1>> m{extents<int, 1>{}, span{s}};
+}
+
+void test_construction_from_extents_and_span_2() {
+    using Ext = extents<unsigned char, 130>;
+    array<ConvertibleToInt<int>, 1> a{{{.val = 2}}};
+    const span s{a};
+    // REQUIRED-SPAN-SIZE(e, s) must be representable as a value of type index_type
+    [[maybe_unused]] layout_stride::mapping<Ext> m{Ext{}, s};
 }
 
 void test_construction_from_strided_layout_mapping() {
@@ -36,9 +61,11 @@ void test_call_operator() {
 int main(int argc, char* argv[]) {
     std_testing::death_test_executive exec;
     exec.add_death_tests({
-        // TRANSITION more tests
-        test_construction_from_extents_and_array,
-        test_construction_from_extents_and_span,
+        test_default_construction,
+        test_construction_from_extents_and_array_1,
+        test_construction_from_extents_and_array_2,
+        test_construction_from_extents_and_span_1,
+        test_construction_from_extents_and_span_2,
         test_construction_from_strided_layout_mapping,
         test_call_operator,
     });

diff --git a/tests/std/tests/P0009R18_mdspan_mdspan_death/env.lst b/tests/std/tests/P0009R18_mdspan_mdspan_death/env.lst
@@ -0,0 +1,4 @@
+# Copyright (c) Microsoft Corporation.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+RUNALL_INCLUDE ..\concepts_latest_matrix.lst
diff --git a/tests/std/tests/P0009R18_mdspan_mdspan_death/test.cpp b/tests/std/tests/P0009R18_mdspan_mdspan_death/test.cpp
@@ -0,0 +1,60 @@
+// Copyright (c) Microsoft Corporation.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#define _CONTAINER_DEBUG_LEVEL 1
+
+#include <array>
+#include <mdspan>
+
+#include <test_death.hpp>
+
+using namespace std;
+
+constexpr array<int, 256> some_ints{};
+
+void test_construction_from_other_mdspan() {
+    auto mds1 = mdspan{some_ints.data(), 8, 2, 8};
+    // For each rank index r of extents_type, static_extent(r) == dynamic_extent || static_extent(r) == other.extent(r)
+    // must be true
+    [[maybe_unused]] mdspan<const int, extents<int, 8, 8, 2>> mds2{mds1};
+}
+
+#ifdef __cpp_multidimensional_subscript // TRANSITION, P2128R6
+void test_access_with_invalid_multidimensional_index_1() {
+    auto mds = mdspan{some_ints.data(), 4, 4};
+    // I must be a multidimensional index in extents()
+    (void) mds[3, 4];
+}
+#endif // __cpp_multidimensional_subscript
+
+void test_access_with_invalid_multidimensional_index_2() {
+    auto mds = mdspan{some_ints.data(), 5, 5};
+    // I must be a multidimensional index in extents()
+    (void) mds[array{4, 5}];
+}
+
+void test_size_when_index_type_is_signed() {
+    auto mds = mdspan{some_ints.data(), dextents<signed char, 3>{8, 8, 4}};
+    // The size of the multidimensional index space extents() must be representable as a value of type size_type
+    (void) mds.size();
+}
+
+void test_size_when_index_type_is_unsigned() {
+    auto mds = mdspan{some_ints.data(), dextents<unsigned char, 3>{8, 8, 4}};
+    // The size of the multidimensional index space extents() must be representable as a value of type size_type
+    (void) mds.size();
+}
+
+int main(int argc, char* argv[]) {
+    std_testing::death_test_executive exec;
+    exec.add_death_tests({
+        test_construction_from_other_mdspan,
+#ifdef __cpp_multidimensional_subscript // TRANSITION, P2128R6
+        test_access_with_invalid_multidimensional_index_1,
+#endif // __cpp_multidimensional_subscript
+        test_access_with_invalid_multidimensional_index_2,
+        test_size_when_index_type_is_signed,
+        test_size_when_index_type_is_unsigned,
+    });
+    return exec.run(argc, argv);
+}