diff options
Diffstat (limited to 'src/corelib/tools/qlist.cpp')
| -rw-r--r-- | src/corelib/tools/qlist.cpp | 34 |
1 files changed, 24 insertions, 10 deletions
diff --git a/src/corelib/tools/qlist.cpp b/src/corelib/tools/qlist.cpp index 5bced19404..0811c3793e 100644 --- a/src/corelib/tools/qlist.cpp +++ b/src/corelib/tools/qlist.cpp @@ -647,7 +647,10 @@ void **QListData::erase(void **xi) \a i must be a valid index position in the list (i.e., 0 <= \a i < size()). - This function is very fast (\l{constant time}). + If this function is called on a list that is currently being shared, it + will trigger a copy of all elements. Otherwise, this function runs in + \l{constant time}. If you do not want to modify the list you should use + QList::at(). \sa at(), value() */ @@ -656,7 +659,7 @@ void **QListData::erase(void **xi) \overload - Same as at(). + Same as at(). This function runs in \l{constant time}. */ /*! \fn QList::reserve(int alloc) @@ -681,10 +684,10 @@ void **QListData::erase(void **xi) This is the same as list.insert(size(), \a value). - This operation is typically very fast (\l{constant time}), - because QList preallocates extra space on both sides of its - internal buffer to allow for fast growth at both ends of the - list. + If this list is not shared, this operation is typically + very fast (amortized \l{constant time}), because QList + preallocates extra space on both sides of its internal + buffer to allow for fast growth at both ends of the list. \sa operator<<(), prepend(), insert() */ @@ -709,8 +712,9 @@ void **QListData::erase(void **xi) This is the same as list.insert(0, \a value). - This operation is usually very fast (\l{constant time}), because - QList preallocates extra space on both sides of its internal + If this list is not shared, this operation is typically + very fast (amortized \l{constant time}), because QList + preallocates extra space on both sides of its internal buffer to allow for fast growth at both ends of the list. \sa append(), insert() @@ -802,7 +806,7 @@ void **QListData::erase(void **xi) same as takeAt(0). This function assumes the list is not empty. To avoid failure, call isEmpty() before calling this function. - This operation takes \l{constant time}. + If this list is not shared, this operation takes \l{constant time}. If you don't use the return value, removeFirst() is more efficient. @@ -817,7 +821,7 @@ void **QListData::erase(void **xi) not empty. To avoid failure, call isEmpty() before calling this function. - This operation takes \l{constant time}. + If this list is not shared, this operation takes \l{constant time}. If you don't use the return value, removeLast() is more efficient. @@ -1288,6 +1292,11 @@ void **QListData::erase(void **xi) iterators over a long period of time, we recommend that you use QLinkedList rather than QList. + \warning Iterators on implicitly shared containers do not work + exactly like STL-iterators. You should avoid copying a container + while iterators are active on that container. For more information, + read \l{Implicit sharing iterator problem}. + \sa QList::const_iterator, QMutableListIterator */ @@ -1538,6 +1547,11 @@ void **QListData::erase(void **xi) iterators over a long period of time, we recommend that you use QLinkedList rather than QList. + \warning Iterators on implicitly shared containers do not work + exactly like STL-iterators. You should avoid copying a container + while iterators are active on that container. For more information, + read \l{Implicit sharing iterator problem}. + \sa QList::iterator, QListIterator */ |