The Q3CacheIterator class provides an iterator for Q3Cache collections. 更多...
| 头： | #include <Q3CacheIterator> |
| Q3CacheIterator (const Q3Cache<type> & cache ) | |
| Q3CacheIterator (const Q3CacheIterator<type> & ci ) | |
| bool | atFirst () const |
| bool | atLast () const |
| uint | count () const |
| type * | current () const |
| QString | currentKey () const |
| bool | isEmpty () const |
| type * | toFirst () |
| type * | toLast () |
| operator type * () const | |
| type * | operator() () |
| type * | operator++ () |
| type * | operator+= (uint jump ) |
| type * | operator-- () |
| type * | operator-= (uint jump ) |
| Q3CacheIterator<type> & | operator= (const Q3CacheIterator<type> & ci ) |
The Q3CacheIterator class provides an iterator for Q3Cache collections.
Note that the traversal order is arbitrary; you are not guaranteed any particular order. If new objects are inserted into the cache while the iterator is active, the iterator may or may not see them.
Multiple iterators are completely independent, even when they operate on the same Q3Cache . Q3Cache updates all iterators that refer an item when that item is removed.
Q3CacheIterator provides an operator++(), and an operator+=() to traverse the cache. The current () 和 currentKey () functions are used to access the current cache item and its key. The atFirst () 和 atLast () return TRUE if the iterator points to the first or last item in the cache respectively. The isEmpty () function returns TRUE if the cache is empty, and count () returns the number of items in the cache.
注意， atFirst () 和 atLast () refer to the iterator's arbitrary ordering, not to the cache's internal least recently used list.
另请参阅 Q3Cache .
Constructs an iterator for cache . The current iterator item is set to point to the first item in the cache .
Constructs an iterator for the same cache as ci . The new iterator starts at the same item as ci. current (), but moves independently from there on.
Returns TRUE if the iterator points to the first item in the cache; otherwise returns FALSE. Note that this refers to the iterator's arbitrary ordering, not to the cache's internal least recently used list.
Returns TRUE if the iterator points to the last item in the cache; otherwise returns FALSE. Note that this refers to the iterator's arbitrary ordering, not to the cache's internal least recently used list.
Returns the number of items in the cache on which this iterator operates.
另请参阅 isEmpty ().
Returns a pointer to the current iterator item.
Returns the key for the current iterator item.
Returns TRUE if the cache is empty, i.e. count () == 0; otherwise it returns FALSE.
另请参阅 count ().
Sets the iterator to point to the first item in the cache and returns a pointer to the item.
Sets the iterator to 0 and returns 0 if the cache is empty.
Sets the iterator to point to the last item in the cache and returns a pointer to the item.
Sets the iterator to 0 and returns 0 if the cache is empty.
Cast operator. Returns a pointer to the current iterator item. Same as current ().
Makes the succeeding item current and returns the original current item.
If the current iterator item was the last item in the cache or if it was 0, 0 is returned.
Prefix++ makes the iterator point to the item just after current () and makes that the new current item for the iterator. If current () was the last item, operator++() returns 0.
Returns the item jump positions after the current item, or 0 if it is beyond the last item. Makes this the current item.
Prefix-- makes the iterator point to the item just before current () and makes that the new current item for the iterator. If current () was the first item, operator--() returns 0.
Returns the item jump positions before the current item, or 0 if it is before the first item. Makes this the current item.
Makes this an iterator for the same cache as ci . The new iterator starts at the same item as ci. current (), but moves independently thereafter.
