Fix PR34298 - Allow std::function with an incomplete return type.
This patch fixes llvm.org/PR34298. Previously libc++ incorrectly evaluated
the __invokable trait via the converting constructor `function(Tp)` [with Tp = std::function]
whenever the copy constructor or copy assignment operator
was required. This patch further constrains that constructor to short
circut before evaluating the troublesome SFINAE when `Tp` matches
std::function.
The original patch is from Alex Lorenz.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@312892 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed