HP Integrity NonStop J-Series - Manual (Page 97)

//4 Allocate enough space from the RWFileManager to store the birthday. Function
binaryStoreSize() is a member function in most Rogue Wave classes. It returns the number
of bytes necessary to store an object in an
RWFile . If you are storing an entire
RWCollection , or using one of the methods recursiveSaveOn() or operator<<(RWFile&,
RWCollectable), be sure to use recursiveStoreSize() instead.
//5 Seek to the location where the RWDate will be stored.
//6 Store the date at that location. Most Rogue Wave classes have an overloaded version of the
streaming operators << and >>.
//7 Insert the key and offset to the object in the B-tree.
Having stored the names and birthdates on a file, here's how you might retrieve them:
#include
#include
#include
#include
#include
main(){
RWCString name;
RWDate birthday;
RWFileManager fm("birthday.dat");
RWBTreeOnDisk btree(fm);
while(1)
{
cout << "Give name: ";
if (!( cin >> name)) break; // 1
RWoffset loc = btree.findValue(name); // 2
if (loc==RWNIL) // 3
cerr << "Not found.\n";
else
{
fm.SeekTo(loc); // 4
fm >> birthday; // 5
cout << "Birthday is " << birthday << endl; // 6
}
}
return 0;
}
Here is a description of the program: