* \return An offset to space allocated within \blob to which \to_write bytes
* can be written, (or -1 in case of any allocation error).
*/
-ssize_t
+intptr_t
blob_reserve_bytes(struct blob *blob, size_t to_write);
/**
* space. Note that this must be used if later reading with \sa
* blob_read_uint32, since it aligns the offset correctly.
*/
-ssize_t
+intptr_t
blob_reserve_uint32(struct blob *blob);
/**
* space. Note that this must be used if later reading with \sa
* blob_read_intptr, since it aligns the offset correctly.
*/
-ssize_t
+intptr_t
blob_reserve_intptr(struct blob *blob);
/**