issign           1558 complex.c      issign(int c)
issign             57 ext/date/date_parse.c #define issign(c) ((c) == '-' || (c) == '+')
issign             56 ext/date/date_strptime.c #define issign(c) ((c) == '-' || (c) == '+')
issign           2121 rational.c     issign(int c)