|Important||This document may not represent best practices for current development, links to downloads and other resources may no longer be valid. Current recommended version can be found here.|
A dictionary collection class that maps unique CString objects to CObject pointers.
Once you have inserted a CString-CObject* pair (element) into the map, you can efficiently retrieve or delete the pair using a string or a CString value as a key. You can also iterate over all the elements in the map.
A variable of type POSITION is used for alternate entry access in all map variations. You can use a POSITION to "remember" an entry and to iterate through the map. You might think that this iteration is sequential by key value; it is not. The sequence of retrieved elements is indeterminate.
CMapStringToOb incorporates the IMPLEMENT_SERIAL macro to support serialization and dumping of its elements. Each element is serialized in turn if a map is stored to an archive, either with the overloaded insertion (<<) operator or with the Serialize member function.
If you need a diagnostic dump of the individual elements in the map (the CString value and the CObject contents), you must set the depth of the dump context to 1 or greater.
When a CMapStringToOb object is deleted, or when its elements are removed, the CString objects and the CObject pointers are removed. The objects referenced by the CObject pointers are not destroyed.
Map class derivation is similar to list derivation. See the article Collections for an illustration of the derivation of a special-purpose list class.