Forbid -d when digit map cannot be shown

-d shows only the digit map and nothing else, so if the digit map cannot
be shown (e.g. radices above 36 without -f), it makes sense to forbid
this rather than print an empty string.

1 files changed, 2 insertions, 0 deletions

diff --git a/args.go b/args.go
index fbb4cf0..0fb12d4 100644
--- a/args.go
+++ b/args.go
@@ -61,6 +61,8 @@ func parseArgs() (args, error) {
 		return args{}, uintParsingError(flag.Arg(0), err)
 	} else if radix < 2 {
 		return args{}, errors.New("Cannot use 0 or 1 as radices.")
+	} else if radix > maxSmallRadix && a.DigitMapOnly && !a.FullMap {
+		return args{}, errors.New("Used -d option, but digit map cannot be shown.")
 	}
 
 	a.Radix = uint(radix)