Q3AsciiDict Class Reference
[Qt3Support module]

Detailed Description

The Q3AsciiDict class is a template class that provides a dictionary based on char* keys.

Q3AsciiDict is implemented as a template class. Define a template instance Q3AsciiDict<X> to create a dictionary that operates on pointers to X (X*).

A dictionary is a collection of key-value pairs. The key is a char* used for insertion, removal and lookup. The value is a pointer. Dictionaries provide very fast insertion and lookup.

Q3AsciiDict cannot handle Unicode keys; use the Q3Dict template instead, which uses QString keys. A Q3Dict has the same performace as a Q3AsciiDict.

Example:

 Q3AsciiDict<QLineEdit> fields; // char* keys, QLineEdit* values
 fields.insert( "forename", new QLineEdit( this ) );
 fields.insert( "surname", new QLineEdit( this ) );

 fields["forename"]->setText( "Homer" );
 fields["surname"]->setText( "Simpson" );

 Q3AsciiDictIterator<QLineEdit> it( fields ); // See Q3AsciiDictIterator
 for( ; it.current(); ++it )
     cout << it.currentKey() << ": " << it.current()->text() << endl;
 cout << endl;

 if ( fields["forename"] && fields["surname"] )
     cout << fields["forename"]->text() << " "
         << fields["surname"]->text() << endl;  // Prints "Homer Simpson"

 fields.remove( "forename" ); // Does not delete the line edit
 if ( ! fields["forename"] )
     cout << "forename is not in the dictionary" << endl;

In this example we use a dictionary to keep track of the line edits we're using. We insert each line edit into the dictionary with a unique name and then access the line edits via the dictionary. See Q3PtrDict, Q3IntDict and Q3Dict.

See Q3Dict for full details, including the choice of dictionary size, and how deletions are handled.

See also Q3AsciiDictIterator, Q3Dict, Q3IntDict, and Q3PtrDict.

Member Function Documentation

 Q3AsciiDict<char> dict;
     ...
 if ( dict.find(key) )
     dict.remove( key );
 dict.insert( key, item );