void buf_output_init(struct buf_output *out);
void buf_output_free(struct buf_output *out);
size_t buf_output_add(struct buf_output *out, const char *buf, size_t len);
void buf_output_init(struct buf_output *out);
void buf_output_free(struct buf_output *out);
size_t buf_output_add(struct buf_output *out, const char *buf, size_t len);