Message ID | 20230308164651.325398-1-ppalka@redhat.com |
---|---|
State | New |
Headers | show |
Series | libstdc++: Implement P2520R0 changes to move_iterator's iterator_concept | expand |
On Wed, 8 Mar 2023 at 16:47, Patrick Palka via Libstdc++ <libstdc++@gcc.gnu.org> wrote: > > Tested on x86_64-pc-linux-gnu, does this look OK for trunk and perhaps > backports? Yes for all. > > libstdc++-v3/ChangeLog: > > * include/bits/stl_iterator.h (move_iterator::_S_iter_concept): > Define. > (__cpp_lib_move_iterator_concept): Define for C++20. > (move_iterator::iterator_concept): Strengthen as per P2520R0. > * include/std/version (__cpp_lib_move_iterator_concept): Define > for C++20. > * testsuite/24_iterators/move_iterator/p2520r0.cc: New test. > --- > libstdc++-v3/include/bits/stl_iterator.h | 20 +++++++++- > libstdc++-v3/include/std/version | 1 + > .../24_iterators/move_iterator/p2520r0.cc | 37 +++++++++++++++++++ > 3 files changed, 57 insertions(+), 1 deletion(-) > create mode 100644 libstdc++-v3/testsuite/24_iterators/move_iterator/p2520r0.cc > > diff --git a/libstdc++-v3/include/bits/stl_iterator.h b/libstdc++-v3/include/bits/stl_iterator.h > index c20dc9ecac5..a6a09dbac16 100644 > --- a/libstdc++-v3/include/bits/stl_iterator.h > +++ b/libstdc++-v3/include/bits/stl_iterator.h > @@ -1465,11 +1465,29 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION > && convertible_to<const _Iter2&, _Iterator>; > #endif > > +#if __cplusplus > 201703L && __cpp_lib_concepts > + static auto > + _S_iter_concept() > + { > + if constexpr (random_access_iterator<_Iterator>) > + return random_access_iterator_tag{}; > + else if constexpr (bidirectional_iterator<_Iterator>) > + return bidirectional_iterator_tag{}; > + else if constexpr (forward_iterator<_Iterator>) > + return forward_iterator_tag{}; > + else > + return input_iterator_tag{}; > + } > +#endif > + > public: > using iterator_type = _Iterator; > > #if __cplusplus > 201703L && __cpp_lib_concepts > - using iterator_concept = input_iterator_tag; > + // This is P2520R0, a C++23 change, but we treat it as a DR against C++20. > +# define __cpp_lib_move_iterator_concept 202207L > + using iterator_concept = decltype(_S_iter_concept()); > + > // iterator_category defined in __move_iter_cat > using value_type = iter_value_t<_Iterator>; > using difference_type = iter_difference_t<_Iterator>; > diff --git a/libstdc++-v3/include/std/version b/libstdc++-v3/include/std/version > index 871d30db5b3..25ebfc3e512 100644 > --- a/libstdc++-v3/include/std/version > +++ b/libstdc++-v3/include/std/version > @@ -289,6 +289,7 @@ > #define __cpp_lib_polymorphic_allocator 201902L > #if __cpp_lib_concepts > # define __cpp_lib_ranges 202110L > +# define __cpp_lib_move_iterator_concept 202207L > #endif > #if __cpp_lib_atomic_wait || _GLIBCXX_HAVE_POSIX_SEMAPHORE > # define __cpp_lib_semaphore 201907L > diff --git a/libstdc++-v3/testsuite/24_iterators/move_iterator/p2520r0.cc b/libstdc++-v3/testsuite/24_iterators/move_iterator/p2520r0.cc > new file mode 100644 > index 00000000000..883d6cc09e0 > --- /dev/null > +++ b/libstdc++-v3/testsuite/24_iterators/move_iterator/p2520r0.cc > @@ -0,0 +1,37 @@ > +// { dg-options "-std=gnu++20" } > +// { dg-do compile { target c++20 } } > + > +// Verify P2520R0 changes to move_iterator's iterator_concept, which we treat > +// as a DR against C++20. > + > +#include <iterator> > +#if __cpp_lib_move_iterator_concept != 202207L > +# error "Feature-test macro __cpp_lib_move_iterator_concept has wrong value in <iterator>" > +#endif > + > +#undef __cpp_lib_move_iterator_concept > +#include <version> > +#if __cpp_lib_move_iterator_concept != 202207L > +# error "Feature-test macro __cpp_lib_move_iterator_concept has wrong value in <version>" > +#endif > + > +#include <testsuite_iterators.h> > + > +using __gnu_test::test_input_range; > +using __gnu_test::test_forward_range; > +using __gnu_test::test_bidirectional_range; > +using __gnu_test::test_random_access_range; > + > +using ty1 = std::move_iterator<decltype(std::declval<test_input_range<int>&>().begin())>; > +static_assert(std::same_as<ty1::iterator_concept, std::input_iterator_tag>); > + > +using ty2 = std::move_iterator<decltype(std::declval<test_forward_range<int>&>().begin())>; > +static_assert(std::same_as<ty2::iterator_concept, std::forward_iterator_tag>); > + > +using ty3 = std::move_iterator<decltype(std::declval<test_bidirectional_range<int>&>().begin())>; > +static_assert(std::same_as<ty3::iterator_concept, std::bidirectional_iterator_tag>); > + > +using ty4 = std::move_iterator<decltype(std::declval<test_random_access_range<int>&>().begin())>; > +static_assert(std::same_as<ty4::iterator_concept, std::random_access_iterator_tag>); > + > +static_assert(std::random_access_iterator<std::move_iterator<int*>>); > -- > 2.40.0.rc0.57.g454dfcbddf >
diff --git a/libstdc++-v3/include/bits/stl_iterator.h b/libstdc++-v3/include/bits/stl_iterator.h index c20dc9ecac5..a6a09dbac16 100644 --- a/libstdc++-v3/include/bits/stl_iterator.h +++ b/libstdc++-v3/include/bits/stl_iterator.h @@ -1465,11 +1465,29 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION && convertible_to<const _Iter2&, _Iterator>; #endif +#if __cplusplus > 201703L && __cpp_lib_concepts + static auto + _S_iter_concept() + { + if constexpr (random_access_iterator<_Iterator>) + return random_access_iterator_tag{}; + else if constexpr (bidirectional_iterator<_Iterator>) + return bidirectional_iterator_tag{}; + else if constexpr (forward_iterator<_Iterator>) + return forward_iterator_tag{}; + else + return input_iterator_tag{}; + } +#endif + public: using iterator_type = _Iterator; #if __cplusplus > 201703L && __cpp_lib_concepts - using iterator_concept = input_iterator_tag; + // This is P2520R0, a C++23 change, but we treat it as a DR against C++20. +# define __cpp_lib_move_iterator_concept 202207L + using iterator_concept = decltype(_S_iter_concept()); + // iterator_category defined in __move_iter_cat using value_type = iter_value_t<_Iterator>; using difference_type = iter_difference_t<_Iterator>; diff --git a/libstdc++-v3/include/std/version b/libstdc++-v3/include/std/version index 871d30db5b3..25ebfc3e512 100644 --- a/libstdc++-v3/include/std/version +++ b/libstdc++-v3/include/std/version @@ -289,6 +289,7 @@ #define __cpp_lib_polymorphic_allocator 201902L #if __cpp_lib_concepts # define __cpp_lib_ranges 202110L +# define __cpp_lib_move_iterator_concept 202207L #endif #if __cpp_lib_atomic_wait || _GLIBCXX_HAVE_POSIX_SEMAPHORE # define __cpp_lib_semaphore 201907L diff --git a/libstdc++-v3/testsuite/24_iterators/move_iterator/p2520r0.cc b/libstdc++-v3/testsuite/24_iterators/move_iterator/p2520r0.cc new file mode 100644 index 00000000000..883d6cc09e0 --- /dev/null +++ b/libstdc++-v3/testsuite/24_iterators/move_iterator/p2520r0.cc @@ -0,0 +1,37 @@ +// { dg-options "-std=gnu++20" } +// { dg-do compile { target c++20 } } + +// Verify P2520R0 changes to move_iterator's iterator_concept, which we treat +// as a DR against C++20. + +#include <iterator> +#if __cpp_lib_move_iterator_concept != 202207L +# error "Feature-test macro __cpp_lib_move_iterator_concept has wrong value in <iterator>" +#endif + +#undef __cpp_lib_move_iterator_concept +#include <version> +#if __cpp_lib_move_iterator_concept != 202207L +# error "Feature-test macro __cpp_lib_move_iterator_concept has wrong value in <version>" +#endif + +#include <testsuite_iterators.h> + +using __gnu_test::test_input_range; +using __gnu_test::test_forward_range; +using __gnu_test::test_bidirectional_range; +using __gnu_test::test_random_access_range; + +using ty1 = std::move_iterator<decltype(std::declval<test_input_range<int>&>().begin())>; +static_assert(std::same_as<ty1::iterator_concept, std::input_iterator_tag>); + +using ty2 = std::move_iterator<decltype(std::declval<test_forward_range<int>&>().begin())>; +static_assert(std::same_as<ty2::iterator_concept, std::forward_iterator_tag>); + +using ty3 = std::move_iterator<decltype(std::declval<test_bidirectional_range<int>&>().begin())>; +static_assert(std::same_as<ty3::iterator_concept, std::bidirectional_iterator_tag>); + +using ty4 = std::move_iterator<decltype(std::declval<test_random_access_range<int>&>().begin())>; +static_assert(std::same_as<ty4::iterator_concept, std::random_access_iterator_tag>); + +static_assert(std::random_access_iterator<std::move_iterator<int*>>);