[Bug c++/70037] New: [concepts] comdat group error and an ICE with a conceptified tuple implementation

[ville.voutilainen at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70037

            Bug ID: 70037
           Summary: [concepts] comdat group error and an ICE with a
                    conceptified tuple implementation
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ville.voutilainen at gmail dot com
  Target Milestone: ---

Created attachment 37838
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=37838&action=edit
Preprocessed test

Having difficulties reducing this, attaching preprocessed source.