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| author | Patrick Palka <ppalka@redhat.com> | 2021-04-27 14:07:46 -0400 |
|---|---|---|
| committer | Patrick Palka <ppalka@redhat.com> | 2021-04-27 14:07:46 -0400 |
| commit | 85ef4b8d4eb3313a48b79c7e752891f9646bb246 (patch) | |
| tree | dd8c1523f84bc420366f16f48c5d019c1ebb25fb /libstdc++-v3 | |
| parent | c605a8bf92708e81d771426a87b3baddc32082dd (diff) | |
| download | gcc-85ef4b8d4eb3313a48b79c7e752891f9646bb246.zip gcc-85ef4b8d4eb3313a48b79c7e752891f9646bb246.tar.gz gcc-85ef4b8d4eb3313a48b79c7e752891f9646bb246.tar.bz2 | |
libstdc++: Fix up lambda in join_view::_Iterator::operator++ [PR100290]
Currently, the return type of this lambda is decltype(auto), so the
lambda ends up returning a copy of _M_parent->_M_inner rather than a
reference to it when _S_ref_glvalue is false. This means _M_inner and
ranges::end(__inner_range) are respectively an iterator and sentinel for
different ranges, so comparing them is undefined.
libstdc++-v3/ChangeLog:
PR libstdc++/100290
* include/std/ranges (join_view::_Iterator::operator++): Correct
the return type of the lambda to avoid returning a copy of
_M_parent->_M_inner.
* testsuite/std/ranges/adaptors/join.cc (test10): New test.
Diffstat (limited to 'libstdc++-v3')
| -rw-r--r-- | libstdc++-v3/include/std/ranges | 2 | ||||
| -rw-r--r-- | libstdc++-v3/testsuite/std/ranges/adaptors/join.cc | 11 |
2 files changed, 12 insertions, 1 deletions
diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges index 74075a2..09115e9 100644 --- a/libstdc++-v3/include/std/ranges +++ b/libstdc++-v3/include/std/ranges @@ -2389,7 +2389,7 @@ namespace views::__adaptor constexpr _Iterator& operator++() { - auto&& __inner_range = [this] () -> decltype(auto) { + auto&& __inner_range = [this] () -> auto&& { if constexpr (_S_ref_is_glvalue) return *_M_outer; else diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/join.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/join.cc index fb06a76..e6c71d7 100644 --- a/libstdc++-v3/testsuite/std/ranges/adaptors/join.cc +++ b/libstdc++-v3/testsuite/std/ranges/adaptors/join.cc @@ -160,6 +160,16 @@ test09() static_assert(!requires { 0 | join; }); } +void +test10() +{ + // PR libstdc++/100290 + auto v = views::single(0) + | views::transform([](const auto& s) { return views::single(s); }) + | views::join; + VERIFY( ranges::next(v.begin()) == v.end() ); +} + int main() { @@ -172,4 +182,5 @@ main() test07(); test08(); test09(); + test10(); } |