On Mon, 7 Jul 2025 at 10:13, Tomasz Kaminski <tkami...@redhat.com> wrote:
>
>
>
> On Mon, Jul 7, 2025 at 11:09 AM Jonathan Wakely <jwak...@redhat.com> wrote:
>>
>> On Fri, 4 Jul 2025 at 09:30, Luc Grosheintz <luc.groshei...@gmail.com> wrote:
>> >
>> > Previously the prerequisite of the extents ctors that
>> >
>> > static_extent(i) == dynamic_extent || extent(i) == other.extent(i).
>> >
>> > was not checked. This commit adds the __glibcxx_assert and test them.
>> >
>> > libstdc++-v3/ChangeLog:
>> >
>> > * include/std/mdspan (extents): Check prerequisite of the ctor that
>> > static_extent(i) == dynamic_extent || extent(i) == other.extent(i).
>> > * testsuite/23_containers/mdspan/extents/class_mandates_neg.cc:
>> > Test the implemented prerequisite.
>> >
>> > Signed-off-by: Luc Grosheintz <luc.groshei...@gmail.com>
>> > ---
>> > libstdc++-v3/include/std/mdspan | 13 +++++++
>> > .../mdspan/extents/class_mandates_neg.cc | 2 ++
>> > .../mdspan/extents/extents_mismatch_neg.cc | 35 +++++++++++++++++++
>> > 3 files changed, 50 insertions(+)
>> > create mode 100644
>> > libstdc++-v3/testsuite/23_containers/mdspan/extents/extents_mismatch_neg.cc
>> >
>> > diff --git a/libstdc++-v3/include/std/mdspan
>> > b/libstdc++-v3/include/std/mdspan
>> > index cf20553aaa5..1d6cdc93d80 100644
>> > --- a/libstdc++-v3/include/std/mdspan
>> > +++ b/libstdc++-v3/include/std/mdspan
>> > @@ -110,10 +110,23 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> > return __se;
>> > }
>> >
>> > + template<size_t _OtherRank, typename _GetOtherExtent>
>> > + constexpr bool
>> > + _S_is_compatible_extents(_GetOtherExtent __get_extent) noexcept
>>
>> Was this intended to be a static member function?
>
> Yes, it should be. I will also adjust that locally.
Thanks, OK for trunk with that change.
>>
>>
>> > + {
>> > + if constexpr (_OtherRank == _S_rank)
>> > + for (size_t __i = 0; __i < _S_rank; ++__i)
>> > + if (_Extents[__i] != dynamic_extent
>> > + && !cmp_equal(_Extents[__i],
>> > _S_int_cast(__get_extent(__i))))
>> > + return false;
>> > + return true;
>> > + }
>> > +
>> > template<size_t _OtherRank, typename _GetOtherExtent>
>> > constexpr void
>> > _M_init_dynamic_extents(_GetOtherExtent __get_extent) noexcept
>> > {
>> > +
>> > __glibcxx_assert(_S_is_compatible_extents<_OtherRank>(__get_extent));
>> > for (size_t __i = 0; __i < _S_rank_dynamic; ++__i)
>> > {
>> > size_t __di = __i;
>> > diff --git
>> > a/libstdc++-v3/testsuite/23_containers/mdspan/extents/class_mandates_neg.cc
>> >
>> > b/libstdc++-v3/testsuite/23_containers/mdspan/extents/class_mandates_neg.cc
>> > index f9c1c019666..67d18feda96 100644
>> > ---
>> > a/libstdc++-v3/testsuite/23_containers/mdspan/extents/class_mandates_neg.cc
>> > +++
>> > b/libstdc++-v3/testsuite/23_containers/mdspan/extents/class_mandates_neg.cc
>> > @@ -7,6 +7,8 @@ std::extents<uint8_t, size_t(1) << 9> e1; // { dg-error
>> > "from here" }
>> > std::extents<char, 1> e2; // { dg-error "from here" }
>> > std::extents<bool, 1> e3; // { dg-error "from here" }
>> > std::extents<double, 1> e4; // { dg-error "from here" }
>> > +
>> > // { dg-prune-output "dynamic or representable as IndexType" }
>> > // { dg-prune-output "signed or unsigned integer" }
>> > // { dg-prune-output "invalid use of incomplete type" }
>> > +// { dg-prune-output "non-constant condition for static assertion" }
>> > diff --git
>> > a/libstdc++-v3/testsuite/23_containers/mdspan/extents/extents_mismatch_neg.cc
>> >
>> > b/libstdc++-v3/testsuite/23_containers/mdspan/extents/extents_mismatch_neg.cc
>> > new file mode 100644
>> > index 00000000000..b35e5310d41
>> > --- /dev/null
>> > +++
>> > b/libstdc++-v3/testsuite/23_containers/mdspan/extents/extents_mismatch_neg.cc
>> > @@ -0,0 +1,35 @@
>> > +// { dg-do compile { target c++23 } }
>> > +#include<mdspan>
>> > +
>> > +#include <cstdint>
>> > +
>> > +constexpr size_t dyn = std::dynamic_extent;
>> > +
>> > +constexpr bool
>> > +test_dyn2sta_extents_mismatch_00()
>> > +{
>> > + auto e0 = std::extents<int, dyn>{1};
>> > + [[maybe_unused]] auto e1 = std::extents<int, 2>{e0}; // {
>> > dg-error "expansion of" }
>> > + return true;
>> > +}
>> > +static_assert(test_dyn2sta_extents_mismatch_00()); // {
>> > dg-error "expansion of" }
>> > +
>> > +constexpr bool
>> > +test_dyn2sta_extents_mismatch_01()
>> > +{
>> > + [[maybe_unused]] auto e = std::extents<int, 1, dyn>{2, 2}; // {
>> > dg-error "expansion of" }
>> > + return true;
>> > +}
>> > +static_assert(test_dyn2sta_extents_mismatch_01()); // {
>> > dg-error "expansion of" }
>> > +
>> > +constexpr bool
>> > +test_dyn2sta_extents_mismatch_02()
>> > +{
>> > + std::array<int, 2> exts{2, 2};
>> > + [[maybe_unused]] auto e = std::extents<int, 1, dyn>{exts}; // {
>> > dg-error "expansion of" }
>> > + return true;
>> > +}
>> > +static_assert(test_dyn2sta_extents_mismatch_02()); // {
>> > dg-error "expansion of" }
>> > +
>> > +// { dg-prune-output "non-constant condition for static assertion" }
>> > +// { dg-prune-output "__glibcxx_assert" }
>> > --
>> > 2.49.0
>> >
>>
