[Bug c++/91217] New: Returning std::array from lambda results in an extra copy step on return

[milasudril at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91217

            Bug ID: 91217
           Summary: Returning std::array from lambda results in an extra
                    copy step on return
           Product: gcc
           Version: 8.1.0
               URL: https://godbolt.org/z/3zAhtv
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: milasudril at gmail dot com
  Target Milestone: ---
            Target: ARM, x86-64

It appears that for GCC versions later than or equal to version 8.1, an extra
copy procedure when an std::array is being returned from a lambda. The problem
does not exist for an immediately created function object.

Not affected: GCC 7.4
Affected: GCC 8.1 up to and including trunk.