Implements submdspan for layout_right_padded as described in P3663.
PR libstdc++/110352
libstdc++-v3/ChangeLog:
* include/std/mdspan (layout_right_padded::submdspan_mapping):
New friend method.
* testsuite/23_containers/mdspan/submdspan/submdspan.cc:
Instantiate test for layout_right_padded.
* testsuite/23_containers/mdspan/submdspan/submdspan_mapping.cc:
Ditto.
Signed-off-by: Luc Grosheintz <[email protected]>
---
libstdc++-v3/include/std/mdspan | 43 +++++++++++++++++++
.../mdspan/submdspan/submdspan.cc | 7 ++-
.../mdspan/submdspan/submdspan_mapping.cc | 4 ++
3 files changed, 52 insertions(+), 2 deletions(-)
diff --git a/libstdc++-v3/include/std/mdspan b/libstdc++-v3/include/std/mdspan
index 154213e02a9..15052452425 100644
--- a/libstdc++-v3/include/std/mdspan
+++ b/libstdc++-v3/include/std/mdspan
@@ -1429,20 +1429,54 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
constexpr auto __rank = sizeof...(_Slices);
auto __impl = [&]<size_t... _Is>(index_sequence<_Is...>)
{
return __is_compact_block<
_IndexType, _SubRank, _Slices...[__rank - 1 - _Is]...>();
};
return __impl(make_index_sequence<__rank>());
}
};
+ template<>
+ struct _SubMdspanMapping<_LayoutSide::__right, true>
+ {
+ using _Layout = layout_right;
+ template<size_t _Pad> using _PaddedLayout = layout_right_padded<_Pad>;
+
+ template<typename _Mapping, size_t _Us>
+ static consteval size_t
+ _S_pad()
+ {
+ using _Extents = typename _Mapping::extents_type;
+ constexpr auto __rank = _Extents::rank();
+ constexpr auto __sta_exts = __static_extents<_Extents>(_Us + 1,
__rank - 1);
+ constexpr auto __sta_padstride = __get_static_stride<_Mapping>();
+ if constexpr (__sta_padstride == dynamic_extent
+ || !__all_static(__sta_exts))
+ return dynamic_extent;
+ else
+ return __sta_padstride * __fwd_prod(__sta_exts);
+ }
+
+ template<typename _IndexType, size_t _SubRank, typename... _Slices>
+ static consteval bool
+ _S_is_unpadded_submdspan()
+ {
+ constexpr auto __rank = sizeof...(_Slices);
+ if constexpr (_SubRank == 1)
+ return __is_unit_stride_slice<_Slices...[__rank - 1], _IndexType>;
+ else
+ return false;
+ }
+ };
+
+
template<typename _Mapping>
constexpr auto
__submdspan_mapping_impl(const _Mapping& __mapping)
{ return submdspan_mapping_result{__mapping, 0}; }
template<typename _Mapping, typename... _Slices>
requires (sizeof...(_Slices) > 0)
constexpr auto
__submdspan_mapping_impl(const _Mapping& __mapping, _Slices... __slices)
{
@@ -2822,20 +2856,29 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
extents(), __r + 1, _S_rank - 1)));
}
template<typename _RightPaddedMapping>
requires(__mdspan::__is_right_padded_mapping<_RightPaddedMapping>
&& _RightPaddedMapping::extents_type::rank() == _S_rank)
friend constexpr bool
operator==(const mapping& __self, const _RightPaddedMapping& __other)
noexcept
{ return __self._M_storage._M_equal(__other); }
+
+#if __glibcxx_submdspan
+ private:
+ template<__mdspan::__valid_canonical_slice_type<index_type>... _Slices>
+ requires (extents_type::rank() == sizeof...(_Slices))
+ friend constexpr auto
+ submdspan_mapping(const mapping& __mapping, _Slices... __slices)
+ { return __mdspan::__submdspan_mapping_impl(__mapping, __slices...); }
+#endif // __glibcxx_submdspan
};
#endif // __glibcxx_padded_layouts
template<typename _ElementType>
struct default_accessor
{
static_assert(!is_array_v<_ElementType>,
"ElementType must not be an array type");
static_assert(!is_abstract_v<_ElementType>,
"ElementType must not be an abstract class type");
diff --git a/libstdc++-v3/testsuite/23_containers/mdspan/submdspan/submdspan.cc
b/libstdc++-v3/testsuite/23_containers/mdspan/submdspan/submdspan.cc
index 927b5d06c6b..f8382847fe3 100644
--- a/libstdc++-v3/testsuite/23_containers/mdspan/submdspan/submdspan.cc
+++ b/libstdc++-v3/testsuite/23_containers/mdspan/submdspan/submdspan.cc
@@ -358,17 +358,20 @@ template<typename Layout>
{
test_all_cheap<Layout>();
test_all_expensive<Layout>();
return true;
}
int
main()
{
test_all<std::layout_left>();
+ test_all<std::layout_right>();
+ test_all<std::layout_stride>();
test_all<std::layout_left_padded<1>>();
test_all<std::layout_left_padded<8>>();
test_all<std::layout_left_padded<dyn>>();
- test_all<std::layout_right>();
- test_all<std::layout_stride>();
+ test_all<std::layout_right_padded<1>>();
+ test_all<std::layout_right_padded<8>>();
+ test_all<std::layout_right_padded<dyn>>();
return 0;
}
diff --git
a/libstdc++-v3/testsuite/23_containers/mdspan/submdspan/submdspan_mapping.cc
b/libstdc++-v3/testsuite/23_containers/mdspan/submdspan/submdspan_mapping.cc
index 50836968a06..efd71d10f9d 100644
--- a/libstdc++-v3/testsuite/23_containers/mdspan/submdspan/submdspan_mapping.cc
+++ b/libstdc++-v3/testsuite/23_containers/mdspan/submdspan/submdspan_mapping.cc
@@ -283,15 +283,19 @@ template<typename Layout>
int
main()
{
test_return_types_unpadded_all<std::layout_left>();
test_return_types_unpadded_all<std::layout_right>();
test_return_types_padded_all<std::layout_left_padded<1>>();
test_return_types_padded_all<std::layout_left_padded<2>>();
test_return_types_padded_all<std::layout_left_padded<dyn>>();
+ test_return_types_padded_all<std::layout_right_padded<1>>();
+ test_return_types_padded_all<std::layout_right_padded<2>>();
+ test_return_types_padded_all<std::layout_right_padded<dyn>>();
+
test_layout_stride_return_types();
static_assert(test_layout_stride_return_types());
return 0;
}
--
2.51.2
