Use zip_XXX_t instead of struct zip_XXX or enum zip_XXX.

lib/zip_stat.c

diff --git a/lib/zip_stat.c b/lib/zip_stat.c
index b87182b..cf8e566 100644
--- a/lib/zip_stat.c
+++ b/lib/zip_stat.c
@@ -36,7 +36,7 @@
 
 
 ZIP_EXTERN int
-zip_stat(struct zip *za, const char *fname, zip_flags_t flags, struct zip_stat *st)
+zip_stat(zip_t *za, const char *fname, zip_flags_t flags, zip_stat_t *st)
 {
     zip_int64_t idx;