[Bug c++/55077] New: implement and enable by default -Wliteral-conversion

[manu at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55077

             Bug #: 55077
           Summary: implement and enable by default -Wliteral-conversion
    Classification: Unclassified
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: manu@gcc.gnu.org


>From clang:

test.cc:4:23: warning: implicit conversion from 'double' to 'int' changes value
from 3.1415926 to 3 [-Wliteral-conversion]
 static const int c = 3.1415926;
                  ~   ^~~~~~~~~

This should be fairly easy, since we warn already with -Wconversion:

1) Change the warning flag.
2) Show the values before/after.