In set methods, make the argument const
diff --git a/ndn-cpp/PublisherPublicKeyDigest.hpp b/ndn-cpp/PublisherPublicKeyDigest.hpp
index 5ce4124..95ca25d 100644
--- a/ndn-cpp/PublisherPublicKeyDigest.hpp
+++ b/ndn-cpp/PublisherPublicKeyDigest.hpp
@@ -38,7 +38,7 @@
* Clear this PublisherPublicKeyDigest, and copy from the ndn_PublisherPublicKeyDigest struct.
* @param excludeStruct a C ndn_Exclude struct
*/
- void set(struct ndn_PublisherPublicKeyDigest &publisherPublicKeyDigestStruct)
+ void set(const struct ndn_PublisherPublicKeyDigest &publisherPublicKeyDigestStruct)
{
publisherPublicKeyDigest_.clear();
if (publisherPublicKeyDigestStruct.publisherPublicKeyDigest)