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| author | Patrick Palka <ppalka@redhat.com> | 2020-02-24 16:38:07 -0500 |
|---|---|---|
| committer | Patrick Palka <ppalka@redhat.com> | 2020-02-25 13:04:32 -0500 |
| commit | 510bd1c178f3719df7148dd584d30acc2595dc3c (patch) | |
| tree | 0c8d33fb33c43e3ad04b302c0ab6c6dc898f49e1 | |
| parent | 7f0f108309a881fe9e84a9c0b9a6f13b24a7886e (diff) | |
| download | gcc-510bd1c178f3719df7148dd584d30acc2595dc3c.zip gcc-510bd1c178f3719df7148dd584d30acc2595dc3c.tar.gz gcc-510bd1c178f3719df7148dd584d30acc2595dc3c.tar.bz2 | |
libstdc++: LWG 3301 transform_view::iterator has incorrect iterator_category
libstdc++-v3/ChangeLog:
LWG 3301 transform_view::_Iterator has incorrect iterator_category
* include/std/ranges (transform_view::_Iterator::_S_iter_cat): Adjust
determination of iterator_category as per LWG 3301.
* testsuite/std/ranges/adaptors/transform.cc: Augment test.
| -rw-r--r-- | libstdc++-v3/ChangeLog | 5 | ||||
| -rw-r--r-- | libstdc++-v3/include/std/ranges | 16 | ||||
| -rw-r--r-- | libstdc++-v3/testsuite/std/ranges/adaptors/transform.cc | 24 |
3 files changed, 40 insertions, 5 deletions
diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index 046d50d..1a56a7d2 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,5 +1,10 @@ 2020-02-25 Patrick Palka <ppalka@redhat.com> + LWG 3301 transform_view::_Iterator has incorrect iterator_category + * include/std/ranges (transform_view::_Iterator::_S_iter_cat): Adjust + determination of iterator_category as per LWG 3301. + * testsuite/std/ranges/adaptors/transform.cc: Augment test. + LWG 3292 iota_view is under-constrained * include/std/ranges (iota_view): Require that _Winc models semiregular as per LWG 3292. diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges index ab8fbac..aed90e9 100644 --- a/libstdc++-v3/include/std/ranges +++ b/libstdc++-v3/include/std/ranges @@ -1570,12 +1570,18 @@ namespace views static constexpr auto _S_iter_cat() { - using _Cat - = typename iterator_traits<_Base_iter>::iterator_category; - if constexpr (derived_from<_Cat, contiguous_iterator_tag>) - return random_access_iterator_tag{}; + using _Res = invoke_result_t<_Fp&, range_reference_t<_Base>>; + if constexpr (is_lvalue_reference_v<_Res>) + { + using _Cat + = typename iterator_traits<_Base_iter>::iterator_category; + if constexpr (derived_from<_Cat, contiguous_iterator_tag>) + return random_access_iterator_tag{}; + else + return _Cat{}; + } else - return _Cat{}; + return input_iterator_tag{}; } static constexpr decltype(auto) diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/transform.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/transform.cc index ad51fff..178544d 100644 --- a/libstdc++-v3/testsuite/std/ranges/adaptors/transform.cc +++ b/libstdc++-v3/testsuite/std/ranges/adaptors/transform.cc @@ -77,10 +77,34 @@ test03() VERIFY( ranges::equal(v, (int[]){1,2,3,4,5}) ); } +void +test04() +{ + // LWG 3301 + { + auto f = [] (int x) { return x; }; + int x[] = {1,2,3,4,5}; + auto v = x | views::transform(f); + auto i = v.begin(); + using Cat = decltype(i)::iterator_category; + static_assert(std::same_as<Cat, std::input_iterator_tag>); + } + + { + auto f = [] (int &x) -> int& { return x; }; + int x[] = {1,2,3,4,5}; + auto v = x | views::transform(f); + auto i = v.begin(); + using Cat = decltype(i)::iterator_category; + static_assert(std::derived_from<Cat, std::forward_iterator_tag>); + } +} + int main() { test01(); test02(); test03(); + test04(); } |