-static void read_bytes (struct sfm_reader *, void *, size_t);
-static bool try_read_bytes (struct sfm_reader *, void *, size_t);
-static int read_int (struct sfm_reader *);
-static long long int read_int64 (struct sfm_reader *);
-static void read_string (struct sfm_reader *, char *, size_t);
-static void skip_bytes (struct sfm_reader *, size_t);
+static bool read_bytes (struct sfm_reader *, void *, size_t)
+ WARN_UNUSED_RESULT;
+static int try_read_bytes (struct sfm_reader *, void *, size_t)
+ WARN_UNUSED_RESULT;
+static bool read_int (struct sfm_reader *, int *) WARN_UNUSED_RESULT;
+static bool read_uint (struct sfm_reader *, unsigned int *) WARN_UNUSED_RESULT;
+static bool read_int64 (struct sfm_reader *, long long int *)
+ WARN_UNUSED_RESULT;
+static bool read_uint64 (struct sfm_reader *, unsigned long long int *)
+ WARN_UNUSED_RESULT;
+static bool read_string (struct sfm_reader *, char *, size_t)
+ WARN_UNUSED_RESULT;
+static bool skip_bytes (struct sfm_reader *, size_t) WARN_UNUSED_RESULT;