commit a32a775e66e7141185ef83ca225cbc4799cb70bf
author Eric Fiselier <eric@efcs.ca> Tue Jan 29 18:01:14 2019 +0000
committer Eric Fiselier <eric@efcs.ca> Tue Jan 29 18:01:14 2019 +0000
tree dd43bc4e8427d72b651a5b112647ec70562fc247
parent e0324cb307cc5dd2974faa3e0f2d8693c0aec9a0

Fix PR40495 - is_invokable_v<void> does not compile

The meta-programming that attempted to form the invoke call expression
was not in a SFINAE context. This made it a hard error to provide
non-referencable types like 'void' or 'void (...) const'.

This patch fixes the error by checking the validity of the call
expression within a SFINAE context.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@352522 91177308-0d34-0410-b5e6-96231b3b80d8