sds.c: Add two function prototypes

is_hex_digit and hex_digit_to_int functions had no function prototypes.
Silences two warnings.

1 files changed, 3 insertions, 0 deletions

diff --git a/src/sds.c b/src/sds.c
index f0515f1..f3396c9 100644
--- a/src/sds.c
+++ b/src/sds.c
@@ -33,6 +33,9 @@
 
 #include "sds.h"
 
+int is_hex_digit(char c);
+int hex_digit_to_int(char c);
+
 /* Create a new sds string with the content specified by the 'init' pointer
  * and 'initlen'.
  * If NULL is used for 'init' the string is initialized with zero bytes.