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| author | marshall <mclow.lists@gmail.com> | 2019-11-27 07:13:00 -0800 |
|---|---|---|
| committer | marshall <mclow.lists@gmail.com> | 2019-11-27 07:13:32 -0800 |
| commit | 703c26f03be74daf6e483380e6b23029a3851081 (patch) | |
| tree | 74a4b0cf708652a469975a1f470d401af29111d9 /libcxx/include | |
| parent | f59614d906b5428f3687a44ee018df5840b301dd (diff) | |
| download | bcm5719-llvm-703c26f03be74daf6e483380e6b23029a3851081.tar.gz bcm5719-llvm-703c26f03be74daf6e483380e6b23029a3851081.zip | |
Optimize and fix basic_string move assignment operator. Reviewed as https://reviews.llvm.org/D68623. Thanks to mvels for the patch.
Diffstat (limited to 'libcxx/include')
| -rw-r--r-- | libcxx/include/string | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/libcxx/include/string b/libcxx/include/string index c16dbedc51c..4e0b21135a7 100644 --- a/libcxx/include/string +++ b/libcxx/include/string @@ -2289,10 +2289,20 @@ basic_string<_CharT, _Traits, _Allocator>::__move_assign(basic_string& __str, tr _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value) #endif { - __clear_and_shrink(); - __r_.first() = __str.__r_.first(); - __move_assign_alloc(__str); - __str.__zero(); + if (__is_long()) { + __alloc_traits::deallocate(__alloc(), __get_long_pointer(), + __get_long_cap()); +#if _LIBCPP_STD_VER <= 14 + if (!is_nothrow_move_assignable<allocator_type>::value) { + __set_short_size(0); + traits_type::assign(__get_short_pointer()[0], value_type()); + } +#endif + } + __move_assign_alloc(__str); + __r_.first() = __str.__r_.first(); + __str.__set_short_size(0); + traits_type::assign(__str.__get_short_pointer()[0], value_type()); } template <class _CharT, class _Traits, class _Allocator> |
