[PATCH] D38216: [C++17] Fix class template argument deduction for default constructors without an initializer

[Richard Smith - zygoloid via Phabricator via cfe-commits]

rsmith added a comment.

In https://reviews.llvm.org/D38216#924039, @lichray wrote:

> So gcc got this wrong?
>
>   https://wandbox.org/permlink/RVApvaca1ebUfInn


Yes, the declaration `extern A a;` in that example is ill-formed.


https://reviews.llvm.org/D38216