[PATCH] D38216: [C++17] Fix class template argument deduction for default constructors without an initializer
Zhihao Yuan via Phabricator via cfe-commits
cfe-commits at lists.llvm.org
Sat Nov 11 06:07:10 PST 2017
lichray added a comment.
The standard hasn't allowed deducing any placeholder type without an initializer (10.1.7.4.1 [dcl.type.auto.deduct]/2) yet.
It's unclear to me what
extern A x;
wants to archive. Usually when people writing `extern` then expect an initializer to appear somewhere else, but with this declaration, defining
A x = ...;
later may fail by resolving to a different type, which feels... interesting.
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