[libc++] Revert to previous implementation of __has_rebind
The new implementation introduced in 5b1e5b43 broke the bot running GCC 5.
Cr-Mirrored-From: https://chromium.googlesource.com/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 30cbdcb5c3694e2e6c4647ce88df9e3692bf90cf
diff --git a/include/memory b/include/memory
index 9d56e81..bea55d6 100644
--- a/include/memory
+++ b/include/memory
@@ -841,12 +841,16 @@
typedef _LIBCPP_NODEBUG_TYPE typename _Ptr::difference_type type;
};
-template <class _Tp, class _Up, class = void>
-struct __has_rebind : false_type {};
-
template <class _Tp, class _Up>
-struct __has_rebind<_Tp, _Up,
- typename __void_t<typename _Tp::template rebind<_Up> >::type> : true_type {};
+struct __has_rebind
+{
+private:
+ struct __two {char __lx; char __lxx;};
+ template <class _Xp> static __two __test(...);
+ template <class _Xp> static char __test(typename _Xp::template rebind<_Up>* = 0);
+public:
+ static const bool value = sizeof(__test<_Tp>(0)) == 1;
+};
template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
struct __pointer_traits_rebind