[Bug libstdc++/84535] New: std::thread constructor missing constraint on first argument

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84535

            Bug ID: 84535
           Summary: std::thread constructor missing constraint on first
                    argument
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: redi at gcc dot gnu.org
  Target Milestone: ---

#include <thread>

int main()
{
    static_assert(!std::is_constructible<std::thread, std::thread, int>::value,
"");
}

This assertion fails. The standard requires the constructor to not participate
in overload resolution when the first argument is a std::thread.