Revert "[libc++] Fix PR35491 - std::array of zero-size doesn't work with non-default constructible types."
Revert "Fix initialization of array<const T, 0> with GCC."
Revert "Make array<const T, 0> non-CopyAssignable and make swap and fill ill-formed."
This reverts commit r324182, r324185, and r324194 which were causing issues with zero-length std::arrays.
llvm-svn: 324309
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 936ff58476a9bd12152dd67ca28ce2ed08e97b84
diff --git a/include/array b/include/array
index 068ab50..4eb2fe6 100644
--- a/include/array
+++ b/include/array
@@ -118,57 +118,6 @@
_LIBCPP_BEGIN_NAMESPACE_STD
template <class _Tp, size_t _Size>
-struct __array_traits {
- typedef _Tp _StorageT[_Size];
-
- _LIBCPP_INLINE_VISIBILITY
- static _LIBCPP_CONSTEXPR_AFTER_CXX14 typename remove_const<_Tp>::type*
- __data(typename remove_const<_StorageT>::type& __store) {
- return __store;
- }
-
- _LIBCPP_INLINE_VISIBILITY
- static _LIBCPP_CONSTEXPR_AFTER_CXX14 _Tp const* __data(const _StorageT& __store) {
- return __store;
- }
-
- _LIBCPP_INLINE_VISIBILITY
- static void __swap(_StorageT& __lhs, _StorageT& __rhs) {
- std::swap_ranges(__lhs, __lhs + _Size, __rhs);
- }
-
- _LIBCPP_INLINE_VISIBILITY
- static void __fill(_StorageT& __arr, _Tp const& __val) {
- _VSTD::fill_n(__arr, _Size, __val);
- }
-};
-
-template <class _Tp>
-struct __array_traits<_Tp, 0> {
- typedef typename aligned_storage<sizeof(_Tp), alignment_of<_Tp>::value>::type
- _NonConstStorageT[1];
- typedef typename conditional<is_const<_Tp>::value, const _NonConstStorageT,
- _NonConstStorageT>::type _StorageT;
- typedef typename remove_const<_Tp>::type _NonConstTp;
-
- _LIBCPP_INLINE_VISIBILITY
- static _NonConstTp* __data(_NonConstStorageT &__store) {
- return reinterpret_cast<_NonConstTp*>(__store);
- }
-
- _LIBCPP_INLINE_VISIBILITY
- static const _Tp* __data(const _StorageT &__store) {
- return reinterpret_cast<const _Tp*>(__store);
- }
-
- _LIBCPP_INLINE_VISIBILITY
- static void __swap(_StorageT&, _StorageT&) {}
-
- _LIBCPP_INLINE_VISIBILITY
- static void __fill(_StorageT&, _Tp const&) {}
-};
-
-template <class _Tp, size_t _Size>
struct _LIBCPP_TEMPLATE_VIS array
{
// types:
@@ -185,33 +134,31 @@
typedef std::reverse_iterator<iterator> reverse_iterator;
typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
- typedef __array_traits<_Tp, _Size> _Traits;
- typename _Traits::_StorageT __elems_;
+ value_type __elems_[_Size > 0 ? _Size : 1];
// No explicit construct/copy/destroy for aggregate type
- _LIBCPP_INLINE_VISIBILITY void fill(const value_type& __u) {
- static_assert(_Size != 0 || !is_const<_Tp>::value,
- "cannot fill zero-sized array of type 'const T'");
- _Traits::__fill(__elems_, __u);
- }
+ _LIBCPP_INLINE_VISIBILITY void fill(const value_type& __u)
+ {_VSTD::fill_n(__elems_, _Size, __u);}
+ _LIBCPP_INLINE_VISIBILITY
+ void swap(array& __a) _NOEXCEPT_(_Size == 0 || __is_nothrow_swappable<_Tp>::value)
+ { __swap_dispatch((std::integral_constant<bool, _Size == 0>()), __a); }
_LIBCPP_INLINE_VISIBILITY
- void swap(array& __a)
- _NOEXCEPT_(_Size == 0 || __is_nothrow_swappable<_Tp>::value) {
- static_assert(_Size != 0 || !is_const<_Tp>::value,
- "cannot swap zero-sized array of type 'const T'");
- _Traits::__swap(__elems_, __a.__elems_);
- }
+ void __swap_dispatch(std::true_type, array&) {}
+
+ _LIBCPP_INLINE_VISIBILITY
+ void __swap_dispatch(std::false_type, array& __a)
+ { _VSTD::swap_ranges(__elems_, __elems_ + _Size, __a.__elems_);}
// iterators:
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
- iterator begin() _NOEXCEPT {return iterator(data());}
+ iterator begin() _NOEXCEPT {return iterator(__elems_);}
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
- const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
+ const_iterator begin() const _NOEXCEPT {return const_iterator(__elems_);}
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
- iterator end() _NOEXCEPT {return iterator(data() + _Size);}
+ iterator end() _NOEXCEPT {return iterator(__elems_ + _Size);}
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
- const_iterator end() const _NOEXCEPT {return const_iterator(data() + _Size);}
+ const_iterator end() const _NOEXCEPT {return const_iterator(__elems_ + _Size);}
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
@@ -254,9 +201,9 @@
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference back() const {return __elems_[_Size > 0 ? _Size-1 : 0];}
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
- value_type* data() _NOEXCEPT {return _Traits::__data(__elems_);}
+ value_type* data() _NOEXCEPT {return __elems_;}
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
- const value_type* data() const _NOEXCEPT {return _Traits::__data(__elems_);}
+ const value_type* data() const _NOEXCEPT {return __elems_;}
};
template <class _Tp, size_t _Size>