Constify the API and enable -Wwrite-strings

The API is more similar to printf now.

1 files changed, 2 insertions, 2 deletions

diff --git a/sds.h b/sds.h
index 8b632ff..76d69a8 100644
--- a/sds.h
+++ b/sds.h
@@ -48,8 +48,8 @@ size_t sdslen(const sds s);
 sds sdsdup(const sds s);
 void sdsfree(sds s);
 size_t sdsavail(sds s);
-sds sdscatlen(sds s, void *t, size_t len);
-sds sdscat(sds s, char *t);
+sds sdscatlen(sds s, const void *t, size_t len);
+sds sdscat(sds s, const char *t);
 sds sdscpylen(sds s, char *t, size_t len);
 sds sdscpy(sds s, char *t);