SourcePro : Essential Tools Module User's Guide : Collection Classes : Storage Methods of Collection Classes : Examples of Value-based and Reference-based Collections
Examples of Value-based and Reference-based Collections
Let's look at two code fragments that demonstrate the difference between the value-based and the reference-based procedures.
First, a value-based example:
 
/* A vector of RWCStrings:
*/RWTValOrderedVector<RWCString> v;
 
RWCString s("A string");
v.insert(s);
And a reference-based example:
 
/* A vector of pointers to RWCStrings:
*/RWTPtrOrderedVector<RWCString> v;
 
RWCString* p = new RWCString("A string");
v.insert(p);
Both code fragments insert an RWCString into vector v.
In the first example, s is an RWCString object containing A string. The statement v.insert(s) copies the value of s into the vector. The object that lies within the vector is distinct and separate from the original object s.
In the second example, p is a pointer to the RWCString object. When the procedure v.insert(p) is complete, the new element in v will refer to the same RWCString object as p.