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| author | Patrick Palka <ppalka@redhat.com> | 2024-10-05 13:48:06 -0400 |
|---|---|---|
| committer | Patrick Palka <ppalka@redhat.com> | 2024-10-05 13:48:06 -0400 |
| commit | 7c0d1e9f2a2f1d41d9eb755c36c871d92638c4b7 (patch) | |
| tree | a98dd7c4d4be8bd66a8c5afdb406ac6e7094f4bd | |
| parent | a8e6360765336969e3f45ac16e4340e5e5468768 (diff) | |
| download | gcc-7c0d1e9f2a2f1d41d9eb755c36c871d92638c4b7.zip gcc-7c0d1e9f2a2f1d41d9eb755c36c871d92638c4b7.tar.gz gcc-7c0d1e9f2a2f1d41d9eb755c36c871d92638c4b7.tar.bz2 | |
libstdc++: Implement LWG 3664 changes to ranges::distance
libstdc++-v3/ChangeLog:
* include/bits/ranges_base.h (__distance_fn::operator()):
Adjust iterator/sentinel overloads as per LWG 3664.
* testsuite/24_iterators/range_operations/distance.cc:
Test LWG 3664 example.
Reviewed-by: Jonathan Wakely <jwakely@redhat.com>
| -rw-r--r-- | libstdc++-v3/include/bits/ranges_base.h | 14 | ||||
| -rw-r--r-- | libstdc++-v3/testsuite/24_iterators/range_operations/distance.cc | 11 |
2 files changed, 18 insertions, 7 deletions
diff --git a/libstdc++-v3/include/bits/ranges_base.h b/libstdc++-v3/include/bits/ranges_base.h index 137c3c9..cb2eba1 100644 --- a/libstdc++-v3/include/bits/ranges_base.h +++ b/libstdc++-v3/include/bits/ranges_base.h @@ -947,7 +947,9 @@ namespace ranges struct __distance_fn final { - template<input_or_output_iterator _It, sentinel_for<_It> _Sent> + // _GLIBCXX_RESOLVE_LIB_DEFECTS + // 3664. LWG 3392 broke std::ranges::distance(a, a+3) + template<typename _It, sentinel_for<_It> _Sent> requires (!sized_sentinel_for<_Sent, _It>) constexpr iter_difference_t<_It> operator()[[nodiscard]](_It __first, _Sent __last) const @@ -961,13 +963,11 @@ namespace ranges return __n; } - template<input_or_output_iterator _It, sized_sentinel_for<_It> _Sent> + template<typename _It, sized_sentinel_for<decay_t<_It>> _Sent> [[nodiscard]] - constexpr iter_difference_t<_It> - operator()(const _It& __first, const _Sent& __last) const - { - return __last - __first; - } + constexpr iter_difference_t<decay_t<_It>> + operator()(_It&& __first, _Sent __last) const + { return __last - static_cast<const decay_t<_It>&>(__first); } template<range _Range> [[nodiscard]] diff --git a/libstdc++-v3/testsuite/24_iterators/range_operations/distance.cc b/libstdc++-v3/testsuite/24_iterators/range_operations/distance.cc index 9a1d0c3..3369569 100644 --- a/libstdc++-v3/testsuite/24_iterators/range_operations/distance.cc +++ b/libstdc++-v3/testsuite/24_iterators/range_operations/distance.cc @@ -144,6 +144,16 @@ test05() VERIFY( std::ranges::distance(c4) == 5 ); } +void +test06() +{ + // LWG 3664 - LWG 3392 broke std::ranges::distance(a, a+3) + int a[] = {1, 2, 3}; + VERIFY( std::ranges::distance(a, a+3) == 3 ); + VERIFY( std::ranges::distance(a, a) == 0 ); + VERIFY( std::ranges::distance(a+3, a) == -3 ); +} + int main() { @@ -152,4 +162,5 @@ main() test03(); test04(); test05(); + test06(); } |