On Tue, Jul 22, 2025 at 11:58 AM Tomasz Kaminski <tkami...@redhat.com>
wrote:
>
>
> On Mon, Jul 21, 2025 at 10:19 AM Luc Grosheintz <luc.groshei...@gmail.com>
> wrote:
>
>> All test code of default_accessor can be reused. This commit moves
>> the reuseable code into a file generic.cc and prepares the tests for
>> reuse with aligned_accessor.
>>
>> The AllocatorTrait creates a unified interface for creating both
>> default_accessor<T> and aligned_accessor<T, N> typenames.
>>
>> libstdc++-v3/ChangeLog:
>>
>> * testsuite/23_containers/mdspan/accessors/default.cc: Delete.
>> * testsuite/23_containers/mdspan/accessors/generic.cc: Slightly
>> generalize the test code previously in default.cc.
>>
>> Signed-off-by: Luc Grosheintz <luc.groshei...@gmail.com>
>> ---
>> .../23_containers/mdspan/accessors/default.cc | 99 ------------
>> .../23_containers/mdspan/accessors/generic.cc | 141 ++++++++++++++++++
>> 2 files changed, 141 insertions(+), 99 deletions(-)
>> delete mode 100644
>> libstdc++-v3/testsuite/23_containers/mdspan/accessors/default.cc
>> create mode 100644
>> libstdc++-v3/testsuite/23_containers/mdspan/accessors/generic.cc
>>
>> diff --git
>> a/libstdc++-v3/testsuite/23_containers/mdspan/accessors/default.cc
>> b/libstdc++-v3/testsuite/23_containers/mdspan/accessors/default.cc
>> deleted file mode 100644
>> index c036f8ad10f..00000000000
>> --- a/libstdc++-v3/testsuite/23_containers/mdspan/accessors/default.cc
>> +++ /dev/null
>> @@ -1,99 +0,0 @@
>> -// { dg-do run { target c++23 } }
>> -#include <mdspan>
>> -
>> -#include <testsuite_hooks.h>
>> -
>> -constexpr size_t dyn = std::dynamic_extent;
>> -
>> -template<typename Accessor>
>> - constexpr void
>> - test_accessor_policy()
>> - {
>> - static_assert(std::copyable<Accessor>);
>> - static_assert(std::is_nothrow_move_constructible_v<Accessor>);
>> - static_assert(std::is_nothrow_move_assignable_v<Accessor>);
>> - static_assert(std::is_nothrow_swappable_v<Accessor>);
>> - }
>> -
>> -constexpr bool
>> -test_access()
>> -{
>> - std::default_accessor<double> accessor;
>> - std::array<double, 5> a{10, 11, 12, 13, 14};
>> - VERIFY(accessor.access(a.data(), 0) == 10);
>> - VERIFY(accessor.access(a.data(), 4) == 14);
>> - return true;
>> -}
>> -
>> -constexpr bool
>> -test_offset()
>> -{
>> - std::default_accessor<double> accessor;
>> - std::array<double, 5> a{10, 11, 12, 13, 14};
>> - VERIFY(accessor.offset(a.data(), 0) == a.data());
>> - VERIFY(accessor.offset(a.data(), 4) == a.data() + 4);
>> - return true;
>> -}
>> -
>> -class Base
>> -{ };
>> -
>> -class Derived : public Base
>> -{ };
>> -
>> -constexpr void
>> -test_ctor()
>> -{
>> - // T -> T
>> -
>> static_assert(std::is_nothrow_constructible_v<std::default_accessor<double>,
>> -
>> std::default_accessor<double>>);
>> - static_assert(std::is_convertible_v<std::default_accessor<double>,
>> - std::default_accessor<double>>);
>> -
>> - // T -> const T
>> - static_assert(std::is_convertible_v<std::default_accessor<double>,
>> - std::default_accessor<const
>> double>>);
>> - static_assert(std::is_convertible_v<std::default_accessor<Derived>,
>> - std::default_accessor<const
>> Derived>>);
>> -
>> - // const T -> T
>> - static_assert(!std::is_constructible_v<std::default_accessor<double>,
>> - std::default_accessor<const
>> double>>);
>> - static_assert(!std::is_constructible_v<std::default_accessor<Derived>,
>> - std::default_accessor<const
>> Derived>>);
>> -
>> - // T <-> volatile T
>> - static_assert(std::is_convertible_v<std::default_accessor<int>,
>> - std::default_accessor<volatile
>> int>>);
>> - static_assert(!std::is_constructible_v<std::default_accessor<int>,
>> - std::default_accessor<volatile
>> int>>);
>> -
>> - // size difference
>> - static_assert(!std::is_constructible_v<std::default_accessor<char>,
>> - std::default_accessor<int>>);
>> -
>> - // signedness
>> - static_assert(!std::is_constructible_v<std::default_accessor<int>,
>> - std::default_accessor<unsigned
>> int>>);
>> - static_assert(!std::is_constructible_v<std::default_accessor<unsigned
>> int>,
>> - std::default_accessor<int>>);
>> -
>> - // Derived <-> Base
>> - static_assert(!std::is_constructible_v<std::default_accessor<Base>,
>> - std::default_accessor<Derived>>);
>> - static_assert(!std::is_constructible_v<std::default_accessor<Derived>,
>> - std::default_accessor<Base>>);
>> -
>> -}
>> -
>> -int
>> -main()
>> -{
>> - test_accessor_policy<std::default_accessor<double>>();
>> - test_access();
>> - static_assert(test_access());
>> - test_offset();
>> - static_assert(test_offset());
>> - test_ctor();
>> - return 0;
>> -}
>> diff --git
>> a/libstdc++-v3/testsuite/23_containers/mdspan/accessors/generic.cc
>> b/libstdc++-v3/testsuite/23_containers/mdspan/accessors/generic.cc
>> new file mode 100644
>> index 00000000000..600d152b690
>> --- /dev/null
>> +++ b/libstdc++-v3/testsuite/23_containers/mdspan/accessors/generic.cc
>> @@ -0,0 +1,141 @@
>> +// { dg-do run { target c++23 } }
>> +#include <mdspan>
>> +
>> +#include <testsuite_hooks.h>
>> +
>> +template<typename Accessor>
>> + constexpr bool
>> + test_class_properties()
>> + {
>> + static_assert(std::is_trivially_copyable_v<Accessor>);
>> + static_assert(std::semiregular<Accessor>);
>> + return true;
>> + }
>> +
>> +template<typename Accessor>
>> + constexpr bool
>> + test_accessor_policy()
>> + {
>> + static_assert(std::copyable<Accessor>);
>> + static_assert(std::is_nothrow_move_constructible_v<Accessor>);
>> + static_assert(std::is_nothrow_move_assignable_v<Accessor>);
>> + static_assert(std::is_nothrow_swappable_v<Accessor>);
>> + return true;
>> + }
>> +
>> +class Base
>> +{ };
>> +
>> +class Derived : public Base
>> +{ };
>> +
>> +template<typename AccessorTrait>
>>
> I would make this a template template parameter in form:
> template<template<typename> typename Accessor>
> This way you could pass default_accessor directly, and for aligned accessor
> pass an alias template.
>
Given next commit, we could make a test_properities() with accessor
parameter,
that will call test_class_properties, test_accessor_policy and test_ctor.
> + constexpr bool
>> + test_ctor()
>> + {
>> + // T -> T
>> + static_assert(std::is_nothrow_constructible_v<
>> + typename AccessorTrait::type<double>,
>> + typename AccessorTrait::type<double>>);
>> + static_assert(std::is_convertible_v<
>> + typename AccessorTrait::type<double>,
>> + typename AccessorTrait::type<double>>);
>> +
>> + // T -> const T
>> + static_assert(std::is_convertible_v<
>> + typename AccessorTrait::type<double>,
>> + typename AccessorTrait::type<const double>>);
>> + static_assert(std::is_convertible_v<
>> + typename AccessorTrait::type<Derived>,
>> + typename AccessorTrait::type<const Derived>>);
>> +
>> + // const T -> T
>> + static_assert(!std::is_constructible_v<
>> + typename AccessorTrait::type<double>,
>> + typename AccessorTrait::type<const double>>);
>> + static_assert(!std::is_constructible_v<
>> + typename AccessorTrait::type<Derived>,
>> + typename AccessorTrait::type<const Derived>>);
>> +
>> + // T <-> volatile T
>> + static_assert(std::is_convertible_v<
>> + typename AccessorTrait::type<int>,
>> + typename AccessorTrait::type<volatile int>>);
>> + static_assert(!std::is_constructible_v<
>> + typename AccessorTrait::type<int>,
>> + typename AccessorTrait::type<volatile int>>);
>> +
>> + // size difference
>> + static_assert(!std::is_constructible_v<
>> + typename AccessorTrait::type<char>,
>> + typename AccessorTrait::type<int>>);
>> +
>> + // signedness
>> + static_assert(!std::is_constructible_v<
>> + typename AccessorTrait::type<int>,
>> + typename AccessorTrait::type<unsigned int>>);
>> + static_assert(!std::is_constructible_v<
>> + typename AccessorTrait::type<unsigned int>,
>> + typename AccessorTrait::type<int>>);
>> +
>> + // Derived <-> Base
>> + static_assert(!std::is_constructible_v<
>> + typename AccessorTrait::type<Base>,
>> + typename AccessorTrait::type<Derived>>);
>> + static_assert(!std::is_constructible_v<
>> + typename AccessorTrait::type<Derived>,
>> + typename AccessorTrait::type<Base>>);
>> + return true;
>> + }
>> +
>> +struct DefaultAccessorTrait
>> +{
>> + template<typename T>
>> + using type = std::default_accessor<T>;
>> +};
>> +
>> +static_assert(test_class_properties<std::default_accessor<double>>());
>> +static_assert(test_accessor_policy<std::default_accessor<double>>());
>> +static_assert(test_ctor<DefaultAccessorTrait>());
>> +
>> +template<typename A>
>> + constexpr size_t
>> + accessor_alignment = sizeof(typename A::element_type);
>> +
>> +template<typename Accessor>
>> + constexpr void
>> + test_access(Accessor accessor)
>> + {
>> + constexpr size_t N = accessor_alignment<Accessor>;
>> + alignas(N) std::array<double, 5> a{10, 11, 12, 13, 14};
>> + VERIFY(accessor.access(a.data(), 0) == 10);
>> + VERIFY(accessor.access(a.data(), 4) == 14);
>> + }
>> +
>> +template<typename Accessor>
>> + constexpr void
>> + test_offset(Accessor accessor)
>> + {
>> + constexpr size_t N = accessor_alignment<Accessor>;
>> + alignas(N) std::array<double, 5> a{10, 11, 12, 13, 14};
>> + VERIFY(accessor.offset(a.data(), 0) == a.data());
>> + VERIFY(accessor.offset(a.data(), 4) == a.data() + 4);
>> + }
>> +
>> +template<typename Accessor>
>> + constexpr bool
>> + test_all()
>> + {
>> + auto accessor = Accessor{};
>> + test_offset(accessor);
>> + test_access(accessor);
>> + return true;
>> + }
>> +
>> +int
>> +main()
>> +{
>> + test_all<std::default_accessor<double>>();
>> + static_assert(test_all<std::default_accessor<double>>());
>> + return 0;
>> +}
>> --
>> 2.50.0
>>
>>
