Update documentation.
diff --git a/ndn-cpp/util/blob.hpp b/ndn-cpp/util/blob.hpp
index ed28fe5..bdec7d6 100644
--- a/ndn-cpp/util/blob.hpp
+++ b/ndn-cpp/util/blob.hpp
@@ -11,7 +11,10 @@
namespace ndn {
/**
- * A Blob holds a pointer to an immutable byte array.
+ * A Blob holds a pointer to an immutable byte array. This is like a JavaScript string which is a pointer
+ * to an immutable string. It is OK to pass a pointer to the string because the new owner can't change the bytes
+ * of the string. However, like a JavaScript string, it is possible to change the pointer, and so this does allow
+ * the copy constructor and assignment to change the pointer.
*/
class Blob {
public:
@@ -27,6 +30,8 @@
/**
* Create a new Blob with an immutable copy of the array in the given vector.
+ * If you want to transfer the array without copying, the the vector has to start as a
+ * ptr_lib::shared_ptr<std::vector<unsigned char> > and you can use the Blob constructor with this type.
* @param value A reference to a vector which is copied.
*/
Blob(const std::vector<unsigned char> &value)