Pure CORBA

Nil Object Reference

In general, it is illegal for null pointers (C++) or null references (Java) to be passed as arguments to CORBA operations when concrete values are expected. For example, if an empty string is to be passed as an in parameter, it must be represented as the string "" rather than a null value.

Object references are a special case, however. It is permissible to pass an empty value for an object reference—these are known as nil object references. The representation of nil object references depends on the language mapping.

The reason nil object references are permitted is that it is often useful to supply one as a default value. For example, a finder operation might return a nil value to indicate that an object reference was not ...