rb_cstr_to_dbl    984 ext/tk/tkutil/tkutil.c     return rb_float_new(rb_cstr_to_dbl(RSTRING_PTR(value), 1));
rb_cstr_to_dbl    459 include/ruby/intern.h double rb_cstr_to_dbl(const char*, int);
rb_cstr_to_dbl   2225 object.c           return rb_cstr_to_dbl(s, badcheck);