1berry/qtbase
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Doc: Give advice on foreach vs range-based for

Browse Source 
Task-number: QTBUG-41636
Change-Id: I28c1424e7f4c1c4da596bcae66283b60f471a8ee
Reviewed-by: Martin Smith <martin.smith@digia.com>
This commit is contained in:
Kai Koehne 2015-06-26 16:57:32 +02:00
parent 5a3fe3e97a
commit 04b9f86561
1 changed files with 7 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
src/corelib/doc/src/containers.qdoc
View File

@ -601,6 +601,13 @@
container. It only affects the copy, which is probably not what you container. It only affects the copy, which is probably not what you
want. want.
An alternative to Qt's \c foreach loop is the range-based \c for that is
part of C++ 11 and newer. However, keep in mind that the range-based
\c for might force a Qt container to \l{Implicit Sharing}{detach}, whereas
\c foreach would not. But using \c foreach always copies the container,
which is usually not cheap for STL containers. If in doubt, prefer
\c foreach for Qt containers, and range based \c for for STL ones.
In addition to \c foreach, Qt also provides a \c forever In addition to \c foreach, Qt also provides a \c forever
pseudo-keyword for infinite loops: pseudo-keyword for infinite loops: