OSSL_ENCODER_is_a
if (select_name != NULL && !OSSL_ENCODER_is_a(k, select_name))
if (!OSSL_ENCODER_is_a(next_encoder, current_output_type)) {
match = OSSL_ENCODER_is_a(encoder,
int OSSL_ENCODER_is_a(const OSSL_ENCODER *encoder, const char *name);