https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78996
Bug ID: 78996
Summary: <variant> uses macro as name
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: webrown.cpp at gmail dot com
Target Milestone: ---
Upon upgrading to g++-mp-7 (MacPorts gcc7 7-20170101_0) 7.0.0 20170101
(experimental) and compiling with significant options -std=c++1z -fconcepts, I
find a previously-unseen conflict.
At line 607, header <variant> employs the identifier __unused as the name of a
template parameter pack.
Unfortunately, before #including <variant>, my test program has already
#included <sys/cdefs.h>, which on my system contains the line:
#define __unused __attribute__((unused))
This seems the source of the conflict that now produces diagnostics from the
unchanged test program that last month compiled cleanly.
Preprocessed source is attached. Thank you.
