[PATCH v1 2/6] libstdc++: Add tests for layout_left.
Luc Grosheintz
luc.grosheintz@gmail.com
Tue May 20 08:24:38 GMT 2025
On 5/19/25 2:56 PM, Tomasz Kaminski wrote:
> On Sun, May 18, 2025 at 10:14 PM Luc Grosheintz <luc.grosheintz@gmail.com>
> wrote:
>
>> Implements a suite of tests for the currently implemented parts of
>> layout_left. The individual tests are templated over the layout type, to
>> allow reuse as more layouts are added.
>>
>> libstdc++-v3/ChangeLog:
>>
>> * testsuite/23_containers/mdspan/layouts/class_mandate_neg.cc: New
>> test.
>> * testsuite/23_containers/mdspan/layouts/ctors.cc: New test.
>> * testsuite/23_containers/mdspan/layouts/mapping.cc: New test.
>>
>> Signed-off-by: Luc Grosheintz <luc.grosheintz@gmail.com>
>> ---
>> .../mdspan/layouts/class_mandate_neg.cc | 22 +
>> .../23_containers/mdspan/layouts/ctors.cc | 258 ++++++++++
>> .../23_containers/mdspan/layouts/mapping.cc | 445 ++++++++++++++++++
>> 3 files changed, 725 insertions(+)
>> create mode 100644
>> libstdc++-v3/testsuite/23_containers/mdspan/layouts/class_mandate_neg.cc
>> create mode 100644
>> libstdc++-v3/testsuite/23_containers/mdspan/layouts/ctors.cc
>> create mode 100644
>> libstdc++-v3/testsuite/23_containers/mdspan/layouts/mapping.cc
>>
>> diff --git
>> a/libstdc++-v3/testsuite/23_containers/mdspan/layouts/class_mandate_neg.cc
>> b/libstdc++-v3/testsuite/23_containers/mdspan/layouts/class_mandate_neg.cc
>> new file mode 100644
>> index 00000000000..f122541b3e8
>> --- /dev/null
>> +++
>> b/libstdc++-v3/testsuite/23_containers/mdspan/layouts/class_mandate_neg.cc
>> @@ -0,0 +1,22 @@
>> +// { dg-do compile { target c++23 } }
>> +#include<mdspan>
>> +
>> +#include <cstdint>
>> +
>> +constexpr size_t dyn = std::dynamic_extent;
>> +static constexpr size_t n = (size_t(1) << 7) - 1;
>>
> I would use numeric_limits_max<unit8_t> here.
>
>> +
>> +template<typename Layout>
>> + struct A
>> + {
>> + typename Layout::mapping<std::extents<uint8_t>> m0;
>> + typename Layout::mapping<std::extents<uint8_t, n, 2, dyn>> m1;
>> + typename Layout::mapping<std::extents<uint8_t, n, 2, 0>> m2;
>> +
>> + using extents_type = std::extents<uint8_t, n, 4>;
>> + typename Layout::mapping<extents_type> m3; // { dg-error "required
>> from" }
>> + };
>> +
>> +A<std::layout_left> a_left; // { dg-error "required
>> from" }
>> +
>> +// { dg-prune-output "must be representable as index_type" }
>> diff --git a/libstdc++-v3/testsuite/23_containers/mdspan/layouts/ctors.cc
>> b/libstdc++-v3/testsuite/23_containers/mdspan/layouts/ctors.cc
>> new file mode 100644
>> index 00000000000..4592a05dec8
>> --- /dev/null
>> +++ b/libstdc++-v3/testsuite/23_containers/mdspan/layouts/ctors.cc
>> @@ -0,0 +1,258 @@
>> +// { dg-do run { target c++23 } }
>> +#include <mdspan>
>> +
>> +#include <testsuite_hooks.h>
>> +
>> +constexpr size_t dyn = std::dynamic_extent;
>> +
>> +template<typename Mapping, typename OExtents>
>> + constexpr void
>> + verify_from_exts(OExtents exts)
>> + {
>> + auto m = Mapping(exts);
>> + VERIFY(m.extents() == exts);
>> + }
>> +
>> +
>> +template<typename SMapping, typename OMapping>
>> + constexpr void
>> + verify_from_mapping(OMapping other)
>> + {
>> + auto m = SMapping(other);
>> + VERIFY(m.extents() == other.extents());
>> + }
>> +
>> +template<typename Mapping, typename OExtents>
>> + requires (std::__mdspan::__is_extents<OExtents>)
>> + constexpr void
>> + verify(OExtents oexts)
>> + {
>
> In general, wen possible we prefer to not use internal details in tests.
> I would use if constexpr with requires { typename Other::layout_type; }, ie.
> template<typename Mapping, typename Source>
> cosntexpr void
> verify(Source const& src)
> {
> if constexpr (requires { typename Other::layout_type; })
> verify_from_mapping(src)
> else
> verify_from_extents(src);
> }
>
> + auto m = Mapping(oexts);
>> + VERIFY(m.extents() == oexts);
>> + }
>> +
>> +template<typename Mapping, typename OMapping>
>> + requires (std::__mdspan::__standardized_mapping<OMapping>)
>> + constexpr void
>> + verify(OMapping other)
>> + {
>> + constexpr auto rank = Mapping::extents_type::rank();
>> + auto m = Mapping(other);
>> + VERIFY(m.extents() == other.extents());
>> + if constexpr (rank > 0)
>> + for(size_t i = 0; i < rank; ++i)
>> + VERIFY(std::cmp_equal(m.stride(i), other.stride(i)));
>>
> Why is this not checked in verify_from_mapping?
>
>> + }
>> +
>> +
>> +template<typename To, typename From>
>> + constexpr void
>> + verify_nothrow_convertible(From from)
>> + {
>> + static_assert(std::is_nothrow_constructible_v<To, From>);
>>
> I would call `verify_convertible` here, instead of these two lines.
>
>> + static_assert(std::is_convertible_v<From, To>);
>> + verify<To>(from);
>> + }
>> +
>> +template<typename To, typename From>
>> + constexpr void
>> + verify_convertible(From from)
>> + {
>> + static_assert(std::is_convertible_v<From, To>);
>> + verify<To>(from);
>> + }
>> +
>> +template<typename To, typename From>
>> + constexpr void
>> + verify_constructible(From from)
>> + {
>> + static_assert(!std::is_convertible_v<From, To>);
>> + static_assert(!std::is_nothrow_constructible_v<To, From>);
>>
> Implementations are allowed to add noexcept on the functions, so I would
> not perform this checks.
> See: https://eel.is/c++draft/res.on.exception.handling#5
>
>> + static_assert(std::is_constructible_v<To, From>);
>> + verify<To>(from);
>> + }
>> +
>> +template<typename To, typename From>
>> + constexpr void
>> + verify_nothrow_constructible(From from)
>> + {
>> + static_assert(!std::is_convertible_v<From, To>);
>> + static_assert(std::is_nothrow_constructible_v<To, From>);
>>
> With the change above, I would call verify verify_constructible.
>
>> + verify<To>(from);
>> + }
>> +
>> +template<typename Mapping, typename OExtents>
>> + constexpr void
>> + assert_not_constructible()
>> + {
>> + static_assert(!std::is_constructible_v<Mapping, OExtents>);
>> + }
>> +
>> +// ctor: mapping(const extents&)
>> +namespace from_extents
>> +{
>> + template<typename Layout, typename Extents, typename OExtents>
>> + constexpr void
>> + verify_nothrow_convertible(OExtents oexts)
>> + {
>> + using Mapping = typename Layout::mapping<Extents>;
>> + ::verify_nothrow_convertible<Mapping>(oexts);
>> + }
>> +
>> + template<typename Layout, typename Extents, typename OExtents>
>> + constexpr void
>> + verify_nothrow_constructible(OExtents oexts)
>> + {
>> + using Mapping = typename Layout::mapping<Extents>;
>> + ::verify_nothrow_constructible<Mapping>(oexts);
>> + }
>> +
>> + template<typename Layout, typename Extents, typename OExtents>
>> + constexpr void
>> + assert_not_constructible()
>> + {
>> + using Mapping = typename Layout::mapping<Extents>;
>> + ::assert_not_constructible<Mapping, OExtents>();
>> + }
>> +
>> + template<typename Layout>
>> + constexpr bool
>> + test_ctor()
>> + {
>> + verify_nothrow_convertible<Layout, std::extents<int>>(
>> + std::extents<int>{});
>> +
>> + verify_nothrow_convertible<Layout, std::extents<int, 2>>(
>> + std::extents<int, 2>{});
>> +
>> + verify_nothrow_convertible<Layout, std::extents<int, dyn, 3>>(
>> + std::extents<int, dyn, 3>{2});
>> +
>> + verify_nothrow_constructible<Layout, std::extents<unsigned int>>(
>> + std::extents<int>{});
>> +
>> + verify_nothrow_constructible<Layout, std::extents<int, dyn>>(
>> + std::extents<int, 2>{});
>> +
>> + verify_nothrow_constructible<Layout, std::extents<int, dyn, 3>>(
>> + std::extents<int, 2, 3>{});
>> +
>> + assert_not_constructible<Layout, std::extents<int>,
>> + std::extents<unsigned int>>();
>> + assert_not_constructible<Layout, std::extents<int, 2>,
>> + std::extents<int, dyn>>();
>> + assert_not_constructible<Layout, std::extents<int, 2, 3>,
>> + std::extents<int, dyn, 3>>();
>> + return true;
>> + }
>> +
>> + template<typename Layout, typename Extents>
>> + constexpr void
>> + assert_deducible(Extents exts)
>> + {
>> + typename Layout::mapping m(exts);
>> + static_assert(std::same_as<decltype(m),
>> + typename Layout::mapping<Extents>>);
>> + }
>> +
>> + template<typename Layout>
>> + constexpr void
>> + test_deducible()
>> + {
>> + assert_deducible<Layout>(std::extents<int>());
>> + assert_deducible<Layout>(std::extents<int, 1>());
>> + assert_deducible<Layout>(std::extents<int, 1, 2, dyn>(3));
>> + }
>> +
>> + template<typename Layout>
>> + constexpr void
>> + test_all()
>> + {
>> + test_ctor<Layout>();
>> + static_assert(test_ctor<Layout>());
>> + test_deducible<Layout>();
>> + }
>> +}
>> +
>> +// ctor: mapping(mapping<OExtents>)
>> +namespace from_same_layout
>> +{
>> + template<typename Layout, typename Extents, typename OExtents>
>> + constexpr void
>> + verify_nothrow_convertible(OExtents exts)
>> + {
>> + using Mapping = typename Layout::mapping<Extents>;
>> + using OMapping = typename Layout::mapping<OExtents>;
>> +
>> + ::verify_nothrow_convertible<Mapping>(OMapping(exts));
>> + }
>> +
>> + template<typename Layout, typename Extents, typename OExtents>
>> + constexpr void
>> + verify_nothrow_constructible(OExtents exts)
>> + {
>> + using Mapping = typename Layout::mapping<Extents>;
>> + using OMapping = typename Layout::mapping<OExtents>;
>> +
>> + ::verify_nothrow_constructible<Mapping>(OMapping(exts));
>> + }
>> +
>> + template<typename Layout>
>> + constexpr bool
>> + test_ctor()
>> + {
>> + verify_nothrow_convertible<Layout, std::extents<unsigned int>>(
>> + std::extents<int>{});
>> +
>> + verify_nothrow_constructible<Layout, std::extents<int>>(
>> + std::extents<unsigned int>{});
>> +
>> + assert_not_constructible<
>> + typename Layout::mapping<std::extents<int>>,
>> + typename Layout::mapping<std::extents<int, 1>>>();
>> +
>> + assert_not_constructible<
>> + typename Layout::mapping<std::extents<int, 1>>,
>> + typename Layout::mapping<std::extents<int>>>();
>> +
>> + verify_nothrow_constructible<Layout, std::extents<int, 1>>(
>> + std::extents<int, dyn>{1});
>> +
>> + verify_nothrow_convertible<Layout, std::extents<int, dyn>>(
>> + std::extents<int, 1>{});
>> +
>> + assert_not_constructible<
>> + typename Layout::mapping<std::extents<int, 1, 2>>,
>> + typename Layout::mapping<std::extents<int, 1>>>();
>> +
>> + verify_nothrow_constructible<Layout, std::extents<int, 1, 2>>(
>> + std::extents<int, dyn, 2>{1});
>> +
>> + verify_nothrow_convertible<Layout, std::extents<int, dyn, 2>>(
>> + std::extents<int, 1, 2>{});
>> + return true;
>> + }
>> +
>> + template<typename Layout>
>> + constexpr void
>> + test_all()
>> + {
>> + test_ctor<Layout>();
>> + static_assert(test_ctor<Layout>());
>> + }
>> +}
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_all()
>> + {
>> + from_extents::test_all<Layout>();
>> + from_same_layout::test_all<Layout>();
>> + }
>> +
>> +int
>> +main()
>> +{
>> + test_all<std::layout_left>();
>> + return 0;
>> +}
>> diff --git
>> a/libstdc++-v3/testsuite/23_containers/mdspan/layouts/mapping.cc
>> b/libstdc++-v3/testsuite/23_containers/mdspan/layouts/mapping.cc
>> new file mode 100644
>> index 00000000000..18f3548df67
>> --- /dev/null
>> +++ b/libstdc++-v3/testsuite/23_containers/mdspan/layouts/mapping.cc
>> @@ -0,0 +1,445 @@
>> +// { dg-do run { target c++23 } }
>> +#include <mdspan>
>> +
>> +#include <cstdint>
>> +#include <testsuite_hooks.h>
>> +
>> +constexpr size_t dyn = std::dynamic_extent;
>> +
>> +template<typename Layout, typename Extents>
>> + constexpr bool
>> + test_mapping_properties()
>> + {
>> + using M = typename Layout::mapping<Extents>;
>> + static_assert(std::__mdspan::__is_extents<typename M::extents_type>);
>> + static_assert(std::copyable<M>);
>> + static_assert(std::is_nothrow_move_constructible_v<M>);
>> + static_assert(std::is_nothrow_move_assignable_v<M>);
>> + static_assert(std::is_nothrow_swappable_v<M>);
>> + static_assert(std::is_same_v<typename M::extents_type, Extents>);
>> + static_assert(std::is_same_v<typename M::index_type,
>> + typename M::extents_type::index_type>);
>> + static_assert(std::is_same_v<typename M::size_type,
>> + typename M::extents_type::size_type>);
>> + static_assert(std::is_same_v<typename M::rank_type,
>> + typename M::extents_type::rank_type>);
>> + static_assert(std::is_same_v<typename M::layout_type, Layout>);
>> +
>> + static_assert(std::is_trivially_copyable_v<M>);
>> + static_assert(std::regular<M>);
>> +
>> + static_assert(M::is_always_unique() && M::is_unique());
>> + static_assert(M::is_always_strided() && M::is_strided());
>> + return true;
>> + }
>> +
>> +template<typename Layout>
>> + constexpr bool
>> + test_mapping_properties_all()
>> + {
>> + test_mapping_properties<Layout, std::extents<int>>();
>> + test_mapping_properties<Layout, std::extents<int, 1>>();
>> + test_mapping_properties<Layout, std::extents<int, dyn>>();
>> + test_mapping_properties<Layout, std::extents<int, dyn, dyn>>();
>> + return true;
>> + }
>> +
>> +// Check operator()(Indices...)
>> +template<typename Mapping, size_t N>
>> + constexpr typename Mapping::index_type
>> + linear_index(const Mapping& mapping,
>> + const std::array<typename Mapping::index_type, N>& indices)
>> + {
>> + typename Mapping::index_type ret = 0;
>> + for(size_t r = 0; r < indices.size(); ++r)
>> + ret += indices[r] * mapping.stride(r);
>> + return ret;
>> + }
>> +
>> +template<typename Mapping, typename... Indices>
>> + constexpr void
>> + test_linear_index(const Mapping& m, Indices... i)
>> + {
>> + using index_type = typename Mapping::index_type;
>> + index_type expected = linear_index(m, std::array{index_type(i)...});
>> + VERIFY(m(i...) == expected);
>> + VERIFY(m(uint8_t(i)...) == expected);
>> + }
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_linear_index_0d()
>> + {
>> + constexpr typename Layout::mapping<std::extents<int>> m;
>> + VERIFY(m() == 0);
>> + }
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_linear_index_1d()
>> + {
>> + typename Layout::mapping<std::extents<int, 5>> m;
>> + test_linear_index(m, 0);
>> + test_linear_index(m, 1);
>> + test_linear_index(m, 4);
>> + }
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_linear_index_2d()
>> + {
>> + typename Layout::mapping<std::extents<int, 3, 256>> m;
>> + test_linear_index(m, 0, 0);
>> + test_linear_index(m, 1, 0);
>> + test_linear_index(m, 0, 1);
>> + test_linear_index(m, 1, 1);
>> + test_linear_index(m, 2, 4);
>> + }
>> +
>> +
>> +template<typename Layout>
>> + struct MappingFactory
>> + {
>> + template<typename Extents>
>> + static constexpr typename Layout::mapping<Extents>
>> + create(Extents exts)
>> + { return exts; }
>>
> This call to this function be replaced with:
> typename Layout::mapping<Extents> m(std::extents(3, 5, 7));
> I think expressing this directly would help.
>
This prepares for `layout_stride`. In that case a) the ctor
layout_stride(extents) doesn't exist; and b) we want to have
non-default strides.
The factory will be specialized and return some generic mapping
for any of the three layouts and ranks 0, 1, 2, 3.
>> + };
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_linear_index_3d()
>> + {
>> + auto m = MappingFactory<Layout>::create(std::extents(3, 5, 7));
>> + test_linear_index(m, 0, 0, 0);
>> + test_linear_index(m, 1, 0, 0);
>> + test_linear_index(m, 0, 1, 0);
>> + test_linear_index(m, 0, 0, 1);
>> + test_linear_index(m, 1, 1, 0);
>> + test_linear_index(m, 2, 4, 6);
>> + }
>> +
>> +struct IntLikeA
>> +{
>> + operator int()
>> + { return 0; }
>> +};
>> +
>> +struct IntLikeB
>> +{
>> + operator int() noexcept
>> + { return 0; }
>> +};
>> +
>> +struct NotIntLike
>> +{ };
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_has_linear_index_0d()
>> + {
>> + using Mapping = typename Layout::mapping<std::extents<int>>;
>> + static_assert(std::invocable<Mapping>);
>> + static_assert(!std::invocable<Mapping, int>);
>> + static_assert(!std::invocable<Mapping, IntLikeA>);
>> + static_assert(!std::invocable<Mapping, IntLikeB>);
>> + static_assert(!std::invocable<Mapping, NotIntLike>);
>> + }
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_has_linear_index_1d()
>> + {
>> + using Mapping = typename Layout::mapping<std::extents<int, 3>>;
>> + static_assert(std::invocable<Mapping, int>);
>> + static_assert(!std::invocable<Mapping>);
>> + static_assert(!std::invocable<Mapping, IntLikeA>);
>> + static_assert(std::invocable<Mapping, IntLikeB>);
>> + static_assert(!std::invocable<Mapping, NotIntLike>);
>> + static_assert(std::invocable<Mapping, double>);
>> + }
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_has_linear_index_2d()
>> + {
>> + using Mapping = typename Layout::mapping<std::extents<int, 3, 5>>;
>> + static_assert(std::invocable<Mapping, int, int>);
>> + static_assert(!std::invocable<Mapping, int>);
>> + static_assert(!std::invocable<Mapping, IntLikeA, int>);
>> + static_assert(std::invocable<Mapping, IntLikeB, int>);
>> + static_assert(!std::invocable<Mapping, NotIntLike, int>);
>> + static_assert(std::invocable<Mapping, double, double>);
>> + }
>> +
>> +template<typename Layout>
>> + constexpr bool
>> + test_linear_index_all()
>> + {
>> + test_linear_index_0d<Layout>();
>> + test_linear_index_1d<Layout>();
>> + test_linear_index_2d<Layout>();
>> + test_linear_index_3d<Layout>();
>> + test_has_linear_index_0d<Layout>();
>> + test_has_linear_index_1d<Layout>();
>> + test_has_linear_index_2d<Layout>();
>> + return true;
>> + }
>> +
>> +template<typename Mapping, typename Mapping::index_type... Counts>
>> + constexpr typename Mapping::index_type
>> + linear_index_end_impl(Mapping m,
>> + std::integer_sequence<typename Mapping::index_type, Counts...>)
>>
> I would define this as local lambda inside linear_index_end:
> auto __impl = [&m]<typename Mapping::index_type... Counts>
> {
> // code you have here.
> }
> return _impl(make_index_sequence(...);
>
>> + {
>> + if constexpr (sizeof...(Counts) == 0)
>>
> I do not think you need this special case, it fails from the specification
> below.
> as m((exts.extent(Counts) - 1)...) + 1 becomes m() + 1.
>
>> + return 1;
>> + else
>> + {
>> + auto exts = m.extents();
>> + if(((exts.extent(Counts) == 0) || ...))
>> + return 0;
>> + return m((exts.extent(Counts) - 1)...) + 1;
>> + }
>> + }
>> +
>> +template<typename Mapping>
>> + constexpr typename Mapping::index_type
>> + linear_index_end(Mapping m)
>> + {
>> + using index_type = typename Mapping::index_type;
>> + constexpr size_t rank = Mapping::extents_type::rank();
>> + return linear_index_end_impl(m,
>> + std::make_integer_sequence<index_type, rank>());
>> + }
>> +
>> +// Check required_span_size
>> +template<typename Mapping>
>> + constexpr void
>> + test_required_span_size(Mapping m)
>> + { VERIFY(m.required_span_size() == linear_index_end(m)); }
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_required_span_size_0d()
>> + {
>> + typename Layout::mapping<std::extents<int>> m;
>> + test_required_span_size(m);
>> + }
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_required_span_size_1d()
>> + {
>> + auto m = MappingFactory<Layout>::create(std::extents(3));
>> + test_required_span_size(m);
>> + }
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_required_span_size_2d()
>> + {
>> + auto m = MappingFactory<Layout>::create(std::extents(3, 5));
>> + test_required_span_size(m);
>> + }
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_required_span_size_3d()
>> + {
>> + auto m = MappingFactory<Layout>::create(std::extents(3, 5, 7));
>> + test_required_span_size(m);
>> + }
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_required_span_size_zero_1d()
>> + {
>> + auto m = MappingFactory<Layout>::create(std::extents(3, 0));
>> + test_required_span_size(m);
>> + }
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_required_span_size_zero_3d()
>> + {
>> + auto m = MappingFactory<Layout>::create(std::extents(3, 0, 7));
>> + test_required_span_size(m);
>> + }
>> +
>> +template<typename Layout>
>> + constexpr bool
>> + test_required_span_size_all()
>> + {
>> + test_required_span_size_0d<Layout>();
>> + test_required_span_size_1d<Layout>();
>> + test_required_span_size_2d<Layout>();
>> + test_required_span_size_3d<Layout>();
>> + test_required_span_size_zero_1d<Layout>();
>> + test_required_span_size_zero_3d<Layout>();
>> + return true;
>> + }
>> +
>> +// Check stride
>> +template<typename Layout>
>> + constexpr void
>> + test_stride_1d()
>> + {
>> + std::layout_left::mapping<std::extents<int, 3>> m;
>> + VERIFY(m.stride(0) == 1);
>> + }
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_stride_2d();
>> +
>> +template<>
>> + constexpr void
>> + test_stride_2d<std::layout_left>()
>> + {
>> + std::layout_left::mapping<std::extents<int, 3, 5>> m;
>> + VERIFY(m.stride(0) == 1);
>> + VERIFY(m.stride(1) == 3);
>> + }
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_stride_3d();
>> +
>> +template<>
>> + constexpr void
>> + test_stride_3d<std::layout_left>()
>> + {
>> + std::layout_left::mapping m(std::dextents<int, 3>(3, 5, 7));
>> + VERIFY(m.stride(0) == 1);
>> + VERIFY(m.stride(1) == 3);
>> + VERIFY(m.stride(2) == 3*5);
>> + }
>> +
>> +template<typename Layout>
>> + constexpr bool
>> + test_stride_all()
>> + {
>> + test_stride_1d<Layout>();
>> + test_stride_2d<Layout>();
>> + test_stride_3d<Layout>();
>> + return true;
>> + }
>> +
>> +template<typename Mapping>
>> + concept has_stride = requires (Mapping m)
>> + {
>> + { m.stride(0) } -> std::same_as<typename Mapping::index_type>;
>> + };
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_has_stride_0d()
>> + {
>> + using Mapping = typename Layout::mapping<std::extents<int>>;
>> + constexpr bool expected = false;
>> + static_assert(has_stride<Mapping> == expected);
>> + }
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_has_stride_1d()
>> + { static_assert(has_stride<typename Layout::mapping<std::extents<int,
>> 1>>>); }
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_has_stride_2d()
>> + {
>> + using Extents = std::extents<int, 1, 2>;
>> + static_assert(has_stride<typename Layout::mapping<Extents>>);
>> + }
>> +
>> +// Check operator==
>> +template<typename Layout>
>> + constexpr void
>> + test_eq()
>> + {
>> + typename Layout::mapping<std::extents<int, 1, 2>> m1;
>> + typename Layout::mapping<std::extents<int, 2, 2>> m2;
>> + typename Layout::mapping<std::dextents<int, 2>> m3(m1);
>> +
>> + VERIFY(m1 == m1);
>> + VERIFY(m1 != m2);
>> + VERIFY(m1 == m3);
>> + VERIFY(m2 != m3);
>> + }
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_eq_zero()
>> + {
>> + typename Layout::mapping<std::extents<int, 0, 2>> m1;
>> + typename Layout::mapping<std::extents<int, 0, 2>> m2;
>> + typename Layout::mapping<std::extents<int, 2, 0>> m3;
>> +
>> + VERIFY(m1 == m2);
>> + VERIFY(m1 != m3);
>> + }
>> +
>> +template<typename M1, typename M2>
>> + concept has_op_eq = requires (M1 m1, M2 m2)
>> + {
>> + { m1 == m2 } -> std::same_as<bool>;
>> + { m2 == m1 } -> std::same_as<bool>;
>> + { m1 != m2 } -> std::same_as<bool>;
>> + { m2 != m1 } -> std::same_as<bool>;
>> + };
>> +
>> +template<typename Layout>
>> + constexpr bool
>> + test_has_op_eq()
>> + {
>> + static_assert(!has_op_eq<
>> + typename Layout::mapping<std::extents<int, 1, 2>>,
>> + typename Layout::mapping<std::extents<int, 1>>>);
>> +
>> + static_assert(has_op_eq<
>> + typename Layout::mapping<std::extents<int, 1>>,
>> + typename Layout::mapping<std::extents<int, 1>>>);
>> +
>> + static_assert(has_op_eq<
>> + typename Layout::mapping<std::extents<int, 1>>,
>> + typename Layout::mapping<std::extents<int, 2>>>);
>> + return true;
>> + }
>> +
>> +template<typename Layout>
>> + constexpr bool
>> + test_mapping_all()
>> + {
>> + test_linear_index_all<Layout>();
>> + test_required_span_size_all<Layout>();
>> + test_stride_all<Layout>();
>> +
>> + test_eq<Layout>();
>> + test_eq_zero<Layout>();
>> + return true;
>> + }
>> +
>> +template<typename Layout>
>> + constexpr void
>> + test_all()
>> + {
>> + static_assert(std::is_trivially_default_constructible_v<Layout>);
>> + static_assert(std::is_trivially_copyable_v<Layout>);
>> + static_assert(test_mapping_properties_all<Layout>());
>> +
>> + test_mapping_all<Layout>();
>> + static_assert(test_mapping_all<Layout>());
>> +
>> + test_has_stride_0d<Layout>();
>> + test_has_stride_1d<Layout>();
>> + test_has_stride_2d<Layout>();
>> + test_has_op_eq<Layout>();
>> + }
>> +
>> +int
>> +main()
>> +{
>> + test_all<std::layout_left>();
>> + return 0;
>> +}
>> --
>> 2.49.0
>>
>>
>
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