https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80351
Bug ID: 80351
Summary: Inconsistent warning for constexpr auto constant when
using initializer list (-Wunused-variable)
Product: gcc
Version: 6.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: arnetheduck at gmail dot com
Target Milestone: ---
In the following snippet, these similar variables give different warnings, when
compiled with -Wall - I would expect all of them to not give a warning:
#include <initializer_list>
enum class E { A, B };
constexpr E no_warn2[] = { E::A, E::B };
constexpr auto warn = { E::A, E::B };
constexpr auto no_warn = { E::A, E::B }; // No warning second time around
Results in:
<source>:7:16: warning: 'warn' defined but not used [-Wunused-variable]
constexpr auto warn = { E::A, E::B };
^~~~
Compiler exited with result code 0
See: https://godbolt.org/g/bHGxar
