On Tue, 11 Apr 2023 at 15:58, Patrick Palka via Libstdc++
<libstd...@gcc.gnu.org> wrote:
>
> Tested on x86_64-pc-linux-gnu, does this look OK for trunk/12?
OK for all, thanks.
(This hasn't been approved by LWG yet, but it should be soon.)
>
> libstdc++-v3/ChangeLog:
>
> * include/std/ranges (lazy_split_view::_OuterIter::_OuterIter):
> Propagate _M_trailing_empty in the const-converting constructor
> as per LWG 3904.
> * testsuite/std/ranges/adaptors/adjacent/1.cc (test04): Correct
> assertion.
> * testsuite/std/ranges/adaptors/lazy_split.cc (test12): New test.
> ---
> libstdc++-v3/include/std/ranges | 3 ++-
> .../testsuite/std/ranges/adaptors/adjacent/1.cc | 2 +-
> .../testsuite/std/ranges/adaptors/lazy_split.cc | 16 ++++++++++++++++
> 3 files changed, 19 insertions(+), 2 deletions(-)
>
> diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
> index b230ebefcf5..26a9f2a6872 100644
> --- a/libstdc++-v3/include/std/ranges
> +++ b/libstdc++-v3/include/std/ranges
> @@ -3209,7 +3209,8 @@ namespace views::__adaptor
> _OuterIter(_OuterIter<!_Const> __i)
> requires _Const
> && convertible_to<iterator_t<_Vp>, iterator_t<_Base>>
> - : _M_parent(__i._M_parent), _M_current(std::move(__i._M_current))
> + : _M_parent(__i._M_parent), _M_current(std::move(__i._M_current)),
> + _M_trailing_empty(__i._M_trailing_empty)
> { }
>
> constexpr value_type
> diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/adjacent/1.cc
> b/libstdc++-v3/testsuite/std/ranges/adaptors/adjacent/1.cc
> index 443c1fbf450..19640abfe93 100644
> --- a/libstdc++-v3/testsuite/std/ranges/adaptors/adjacent/1.cc
> +++ b/libstdc++-v3/testsuite/std/ranges/adaptors/adjacent/1.cc
> @@ -107,7 +107,7 @@ test04()
> // PR libstdc++/106798
> auto r = views::single(0) | views::lazy_split(0) | views::pairwise;
> decltype(ranges::cend(r)) s = r.end();
> - VERIFY( r.begin() == s );
> + VERIFY( r.begin() != s );
>
> return true;
> }
> diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/lazy_split.cc
> b/libstdc++-v3/testsuite/std/ranges/adaptors/lazy_split.cc
> index 9df6b3b66a6..4e5c0dc3ed5 100644
> --- a/libstdc++-v3/testsuite/std/ranges/adaptors/lazy_split.cc
> +++ b/libstdc++-v3/testsuite/std/ranges/adaptors/lazy_split.cc
> @@ -22,6 +22,7 @@
> #include <ranges>
> #include <string>
> #include <string_view>
> +#include <utility>
> #include <vector>
> #include <testsuite_hooks.h>
> #include <testsuite_iterators.h>
> @@ -218,6 +219,20 @@ test11()
> static_assert(ranges::distance(views::lazy_split("text"sv, ""sv)) == 4);
> }
>
> +constexpr bool
> +test12()
> +{
> + // LWG 3904
> + auto r = views::single(0) | views::lazy_split(0);
> + auto i = r.begin();
> + ++i;
> + VERIFY( i != r.end() );
> + decltype(std::as_const(r).begin()) j = i;
> + VERIFY( j != r.end() );
> +
> + return true;
> +}
> +
> int
> main()
> {
> @@ -232,4 +247,5 @@ main()
> test09();
> test10();
> test11();
> + static_assert(test12());
> }
> --
> 2.40.0.315.g0607f793cb
>
