[PATCH] D48753: [libcxx] Use custom allocator's `construct` in C++03 when available.

[Volodymyr Sapsai via Phabricator via cfe-commits]

vsapsai added a comment.

In https://reviews.llvm.org/D48753#1147500, @Quuxplusone wrote:

> I'm pretty sure that the C++03 standard doesn't permit the implementation to call any `construct` method here, even if it wanted to. And this adds a couple hundred LOC to get that (non-standard) behavior. Is there a specific use-case that you're trying to enable by adding this behavior to libc++?


Only the standard behaviour is required, so I need only

  template <class _Tp, class _A0>
         static void construct(allocator_type& __a, _Tp* __p, const _A0& __a0);

to call allocator's `construct`. Other `construct` methods with different number of parameters were changed only for completeness. Also I'm thinking that using available matching allocator methods is something that developers would expect. But I don't think this opinion should influence decisions because seems there is no much use for custom `allocator_type::construct`.

If nobody thinks all variadic cases should be supported, I'll clean that up.


https://reviews.llvm.org/D48753