oder_inst,
                                          int *was_set);

typedef int OSSL_DECODER_CONSTRUCT(OSSL_DECODER_INSTANCE *decoder_inst,
                                   const OSSL_PARAM *object,
                                   void *construct_data);
typedef void OSSL_DECODER_CLEANUP(void *construct_data);

int OSSL_DECODER_CTX_set_construct(OSSL_DECODER_CTX *ctx,
                                   OSSL_DECODER_CONSTRUCT *construct);
int OSSL_DECODER_CTX_set_construct_data(OSSL_DECODER_CTX *ctx,
  