-snd_util_memhdr_t *snd_util_memhdr_new(int memsize);
-void snd_util_memhdr_free(snd_util_memhdr_t *hdr);
-snd_util_memblk_t *snd_util_mem_alloc(snd_util_memhdr_t *hdr, int size);
-int snd_util_mem_free(snd_util_memhdr_t *hdr, snd_util_memblk_t *blk);
-int snd_util_mem_avail(snd_util_memhdr_t *hdr);
+struct snd_util_memhdr *snd_util_memhdr_new(int memsize);
+void snd_util_memhdr_free(struct snd_util_memhdr *hdr);
+struct snd_util_memblk *snd_util_mem_alloc(struct snd_util_memhdr *hdr, int size);
+int snd_util_mem_free(struct snd_util_memhdr *hdr, struct snd_util_memblk *blk);
+int snd_util_mem_avail(struct snd_util_memhdr *hdr);