[libcxx] Use custom allocator's `construct` in C++03 when available.
Makes libc++ behavior consistent between C++03 and C++11.
Can use `decltype` in C++03 because `include/__config` defines a macro when
`decltype` is not available.
Reviewers: mclow.lists, EricWF, erik.pilkington, ldionne
Reviewed By: ldionne
Subscribers: dexonsmith, cfe-commits, howard.hinnant, ldionne, christof, jkorous, Quuxplusone
Differential Revision: https://reviews.llvm.org/D48753
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@349676 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/memory b/include/memory
index 3e8f593..b012f5b 100644
--- a/include/memory
+++ b/include/memory
@@ -1460,29 +1460,21 @@
#else // _LIBCPP_CXX03_LANG
-#ifndef _LIBCPP_HAS_NO_VARIADICS
+template <class _Alloc, class _Pointer, class _Tp, class = void>
+struct __has_construct : std::false_type {};
-template <class _Alloc, class _Pointer, class ..._Args>
-struct __has_construct
- : false_type
-{
-};
+template <class _Alloc, class _Pointer, class _Tp>
+struct __has_construct<_Alloc, _Pointer, _Tp, typename __void_t<
+ decltype(_VSTD::declval<_Alloc>().construct(_VSTD::declval<_Pointer>(), _VSTD::declval<_Tp>()))
+>::type> : std::true_type {};
-#else // _LIBCPP_HAS_NO_VARIADICS
-
-template <class _Alloc, class _Pointer, class _Args>
-struct __has_construct
- : false_type
-{
-};
-
-#endif // _LIBCPP_HAS_NO_VARIADICS
+template <class _Alloc, class _Pointer, class = void>
+struct __has_destroy : false_type {};
template <class _Alloc, class _Pointer>
-struct __has_destroy
- : false_type
-{
-};
+struct __has_destroy<_Alloc, _Pointer, typename __void_t<
+ decltype(_VSTD::declval<_Alloc>().destroy(_VSTD::declval<_Pointer>()))
+>::type> : std::true_type {};
template <class _Alloc>
struct __has_max_size
@@ -1571,9 +1563,10 @@
}
template <class _Tp, class _A0>
_LIBCPP_INLINE_VISIBILITY
- static void construct(allocator_type&, _Tp* __p, const _A0& __a0)
+ static void construct(allocator_type& __a, _Tp* __p, const _A0& __a0)
{
- ::new ((void*)__p) _Tp(__a0);
+ __construct(__has_construct<allocator_type, _Tp*, const _A0&>(),
+ __a, __p, __a0);
}
template <class _Tp, class _A0, class _A1>
_LIBCPP_INLINE_VISIBILITY
@@ -1721,6 +1714,19 @@
{
::new ((void*)__p) _Tp(_VSTD::forward<_Args>(__args)...);
}
+#else // _LIBCPP_HAS_NO_VARIADICS
+ template <class _Tp, class _A0>
+ _LIBCPP_INLINE_VISIBILITY
+ static void __construct(true_type, allocator_type& __a, _Tp* __p,
+ const _A0& __a0)
+ {__a.construct(__p, __a0);}
+ template <class _Tp, class _A0>
+ _LIBCPP_INLINE_VISIBILITY
+ static void __construct(false_type, allocator_type&, _Tp* __p,
+ const _A0& __a0)
+ {
+ ::new ((void*)__p) _Tp(__a0);
+ }
#endif // _LIBCPP_HAS_NO_VARIADICS
template <class _Tp>