[libc++] Refactor vector::push_back to use vector::emplace

[ldionne]

This removes some duplicate code. I suspect this was originally written that way because vector::emplace didn't exist in C++03 mode, which stopped being relevant when Clang implemented rvalue references in C++03.

[ldionne]

CC @philnik777

[llvmbot]

@llvm/pr-subscribers-libcxx

Author: Louis Dionne (ldionne)

Changes

This removes some duplicate code. I suspect this was originally written that way because vector::emplace didn't exist in C++03 mode, which stopped being relevant when Clang implemented rvalue references in C++03.

---

Full diff: https://github.com/llvm/llvm-project/pull/113481.diff

1 Files Affected:

• (modified) libcxx/include/vector (+2-43)

diff --git a/libcxx/include/vector b/libcxx/include/vector index bfbf1ea1cfc9f0..ce412a829ea8f7 100644 --- a/libcxx/include/vector +++ b/libcxx/include/vector @@ -689,9 +689,9 @@ public: return std::__to_address(this->__begin_); } - _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void push_back(const_reference __x); + _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void push_back(const_reference __x) { emplace_back(__x); } - _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void push_back(value_type&& __x); + _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void push_back(value_type&& __x) { emplace_back(std::move(__x)); } template <class... _Args> _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI @@ -898,9 +898,6 @@ private: __annotate_shrink(__old_size); } - template <class _Up> - _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI inline pointer __push_back_slow_path(_Up&& __x); - template <class... _Args> _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI inline pointer __emplace_back_slow_path(_Args&&... __args); @@ -1491,44 +1488,6 @@ _LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<_Tp, _Allocator>::shrink_to_fit() _NOE } } -template <class _Tp, class _Allocator> -template <class _Up> -_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<_Tp, _Allocator>::pointer -vector<_Tp, _Allocator>::__push_back_slow_path(_Up&& __x) { - allocator_type& __a = this->__alloc(); - __split_buffer<value_type, allocator_type&> __v(__recommend(size() + 1), size(), __a); - // __v.push_back(std::forward<_Up>(__x)); - __alloc_traits::construct(__a, std::__to_address(__v.__end_), std::forward<_Up>(__x)); - __v.__end_++; - __swap_out_circular_buffer(__v); - return this->__end_; -} - -template <class _Tp, class _Allocator> -_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI void -vector<_Tp, _Allocator>::push_back(const_reference __x) { - pointer __end = this->__end_; - if (__end < this->__end_cap()) { - __construct_one_at_end(__x); - ++__end; - } else { - __end = __push_back_slow_path(__x); - } - this->__end_ = __end; -} - -template <class _Tp, class _Allocator> -_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI void vector<_Tp, _Allocator>::push_back(value_type&& __x) { - pointer __end = this->__end_; - if (__end < this->__end_cap()) { - __construct_one_at_end(std::move(__x)); - ++__end; - } else { - __end = __push_back_slow_path(std::move(__x)); - } - this->__end_ = __end; -} - template <class _Tp, class _Allocator> template <class... _Args> _LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<_Tp, _Allocator>::pointer