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| author | Patrick Palka <ppalka@redhat.com> | 2020-03-02 19:39:13 -0500 |
|---|---|---|
| committer | Patrick Palka <ppalka@redhat.com> | 2020-03-03 22:35:34 -0500 |
| commit | 05779e2c89e06d09a6b685797e87723f7906a5ce (patch) | |
| tree | 8fae04431c834ede3aa8d0c7e77a6525bb2274bf | |
| parent | 7f327e8765c25552a1a6ae7d8747f74786f243dd (diff) | |
| download | gcc-05779e2c89e06d09a6b685797e87723f7906a5ce.zip gcc-05779e2c89e06d09a6b685797e87723f7906a5ce.tar.gz gcc-05779e2c89e06d09a6b685797e87723f7906a5ce.tar.bz2 | |
libstdc++: Fix use of is_nothrow_assignable_v in <bits/ranges_uninitialized.h>
We are passing a value type as the first argument to is_nothrow_assignable_v,
but the result of that is inevitably false. Since this predicate is a part of
the condition that guards the corresponding optimizations for these algorithms,
this bug means these optimizations are never used. We should be passing a
reference type to is_nothrow_assignable_v instead.
libstdc++-v3/ChangeLog:
* include/bits/ranges_uninitialized.h
(uninitialized_copy_fn::operator()): Pass a reference type as the first
argument to is_nothrow_assignable_v.
(uninitialized_copy_fn::operator()): Likewise.
(uninitialized_move_fn::operator()): Likewise. Return an in_out_result
with the input iterator stripped of its move_iterator.
(uninitialized_move_n_fn::operator()): Likewise.
(uninitialized_fill_fn::operator()): Pass a reference type as the first
argument to is_nothrow_assignable_v.
(uninitialized_fill_n_fn::operator()): Likewise.
| -rw-r--r-- | libstdc++-v3/ChangeLog | 13 | ||||
| -rw-r--r-- | libstdc++-v3/include/bits/ranges_uninitialized.h | 24 |
2 files changed, 27 insertions, 10 deletions
diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index 640c5be..45ff06d 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,16 @@ +2020-03-04 Patrick Palka <ppalka@redhat.com> + + * include/bits/ranges_uninitialized.h + (uninitialized_copy_fn::operator()): Pass a reference type as the first + argument to is_nothrow_assignable_v. + (uninitialized_copy_fn::operator()): Likewise. + (uninitialized_move_fn::operator()): Likewise. Return an in_out_result + with the input iterator stripped of its move_iterator. + (uninitialized_move_n_fn::operator()): Likewise. + (uninitialized_fill_fn::operator()): Pass a reference type as the first + argument to is_nothrow_assignable_v. + (uninitialized_fill_n_fn::operator()): Likewise. + 2020-03-03 Jonathan Wakely <jwakely@redhat.com> PR libstdc++/94013 diff --git a/libstdc++-v3/include/bits/ranges_uninitialized.h b/libstdc++-v3/include/bits/ranges_uninitialized.h index 01e1cad6..f97a07a 100644 --- a/libstdc++-v3/include/bits/ranges_uninitialized.h +++ b/libstdc++-v3/include/bits/ranges_uninitialized.h @@ -269,7 +269,7 @@ namespace ranges if constexpr (sized_sentinel_for<_ISent, _Iter> && sized_sentinel_for<_OSent, _Out> && is_trivial_v<_OutType> - && is_nothrow_assignable_v<_OutType, + && is_nothrow_assignable_v<_OutType&, iter_reference_t<_Iter>>) { auto __d1 = ranges::distance(__ifirst, __ilast); @@ -316,7 +316,7 @@ namespace ranges using _OutType = remove_reference_t<iter_reference_t<_Out>>; if constexpr (sized_sentinel_for<_Sent, _Out> && is_trivial_v<_OutType> - && is_nothrow_assignable_v<_OutType, + && is_nothrow_assignable_v<_OutType&, iter_reference_t<_Iter>>) { auto __d = ranges::distance(__ofirst, __olast); @@ -354,13 +354,15 @@ namespace ranges if constexpr (sized_sentinel_for<_ISent, _Iter> && sized_sentinel_for<_OSent, _Out> && is_trivial_v<_OutType> - && is_nothrow_assignable_v<_OutType, + && is_nothrow_assignable_v<_OutType&, iter_rvalue_reference_t<_Iter>>) { auto __d1 = ranges::distance(__ifirst, __ilast); auto __d2 = ranges::distance(__ofirst, __olast); - return ranges::copy_n(std::make_move_iterator(__ifirst), - std::min(__d1, __d2), __ofirst); + auto [__in, __out] + = ranges::copy_n(std::make_move_iterator(__ifirst), + std::min(__d1, __d2), __ofirst); + return {std::move(__in).base(), __out}; } else { @@ -404,12 +406,14 @@ namespace ranges using _OutType = remove_reference_t<iter_reference_t<_Out>>; if constexpr (sized_sentinel_for<_Sent, _Out> && is_trivial_v<_OutType> - && is_nothrow_assignable_v<_OutType, + && is_nothrow_assignable_v<_OutType&, iter_rvalue_reference_t<_Iter>>) { auto __d = ranges::distance(__ofirst, __olast); - return ranges::copy_n(std::make_move_iterator(__ifirst), - std::min(__n, __d), __ofirst); + auto [__in, __out] + = ranges::copy_n(std::make_move_iterator(__ifirst), + std::min(__n, __d), __ofirst); + return {std::move(__in).base(), __out}; } else { @@ -436,7 +440,7 @@ namespace ranges { using _ValueType = remove_reference_t<iter_reference_t<_Iter>>; if constexpr (is_trivial_v<_ValueType> - && is_nothrow_assignable_v<_ValueType, const _Tp&>) + && is_nothrow_assignable_v<_ValueType&, const _Tp&>) return ranges::fill(__first, __last, __x); else { @@ -469,7 +473,7 @@ namespace ranges { using _ValueType = remove_reference_t<iter_reference_t<_Iter>>; if constexpr (is_trivial_v<_ValueType> - && is_nothrow_assignable_v<_ValueType, const _Tp&>) + && is_nothrow_assignable_v<_ValueType&, const _Tp&>) return ranges::fill_n(__first, __n, __x); else { |