-uint8_t* buf_set_ones(uint8_t *buf, int count);
-uint8_t* buf_set_buf(const uint8_t *src, int src_start,
- uint8_t *dst, int dst_start, int len);
+/**
+ * Copies @c size bits out of @c from and into @c to. Any extra
+ * bits in the final byte will be set to zero.
+ * @param from The buffer to copy into @c to.
+ * @param to The buffer that will receive the copy of @c from.
+ * @param size The number of bits to copy.
+ */
+void* buf_cpy(const void *from, void *to, unsigned size);
+
+/**
+ * Set the contents of @c buf with @c count bits, all set to 1.
+ * @param buf The buffer to fill with ones.
+ * @param size The number of bits.
+ * @returns The original buffer (@c buf).
+ */
+void* buf_set_ones(void *buf, unsigned size);