[Bug c++/57183] New: [C++11]auto and -Wunused-variable

[frankhb1989 at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57183



             Bug #: 57183

           Summary: [C++11]auto and -Wunused-variable

    Classification: Unclassified

           Product: gcc

           Version: 4.8.0

            Status: UNCONFIRMED

          Severity: normal

          Priority: P3

         Component: c++

        AssignedTo: unassig...@gcc.gnu.org

        ReportedBy: frankhb1...@gmail.com





Case:

constexpr float PI_0 = 3.1415926F;

constexpr auto PI_1 = 3.1415926F;

const float PI_2 = 3.1415926F;

const auto PI_3 = 3.1415926F;



int main(){}





Using gcc version 4.8.0 (rev2, Built by MinGW-builds project).



g++ a.cc -std=c++11 -Wall

a.cc:2:16: warning: 'PI_1' defined but not used [-Wunused-variable]

 constexpr auto PI_1 = 3.1415926F;

                ^

a.cc:4:12: warning: 'PI_3' defined but not used [-Wunused-variable]

 const auto PI_3 = 3.1415926F;

            ^



The difference between auto and non-auto declarations seems to be not intended.