+/**
+ * Returns the approximate number of bytes needed to allocate a compressor with
+ * wimlib_create_compressor() for the specified compression type, block size,
+ * and parameters. @p params may be @c NULL, in which case the current default
+ * parameters for @p ctype are used. Returns 0 if the compression type or
+ * parameters are invalid.
+ */
+extern uint64_t
+wimlib_get_compressor_needed_memory(enum wimlib_compression_type ctype,
+ size_t max_block_size,
+ const struct wimlib_compressor_params_header *params);
+