<![CDATA[deleting a QMap after clear()]]>Hi,

is it safe to call delete directly after having called clear() on a QMap.
e.g. :

QMap *myMap = new QMap<QString,MyClass>
myMap->insert("one", myClass);
....
myMap->clear();
delete myMap;

]]>https://forum.qt.io/topic/98425/deleting-a-qmap-after-clearRSS for NodeSat, 02 May 2026 01:48:43 GMTFri, 11 Jan 2019 15:34:44 GMT60<![CDATA[Reply to deleting a QMap after clear() on Fri, 11 Jan 2019 18:46:36 GMT]]>And to complete it all together - there is no need to create a QMap on the heap at all in most of the cases.

]]>https://forum.qt.io/post/504168https://forum.qt.io/post/504168Fri, 11 Jan 2019 18:46:36 GMT<![CDATA[Reply to deleting a QMap after clear() on Fri, 11 Jan 2019 16:11:27 GMT]]>@dheerendra
I simply meant that calling clear deletes QMaps internal structures holding the items it manages.
But good call noting if MyClass is a pointer , clear() will not be delete the object being pointed to, but only the pointer itself.

]]>https://forum.qt.io/post/504149https://forum.qt.io/post/504149Fri, 11 Jan 2019 16:11:27 GMT<![CDATA[Reply to deleting a QMap after clear() on Fri, 11 Jan 2019 16:06:25 GMT]]>If your value objects are pointer type, you should delete them as well.

will delete the internal structures.
@mrjj curious about above statement. What do you mean by it ?

]]>https://forum.qt.io/post/504148https://forum.qt.io/post/504148Fri, 11 Jan 2019 16:06:25 GMT<![CDATA[Reply to deleting a QMap after clear() on Fri, 11 Jan 2019 15:47:44 GMT]]>hi and welcome to the forums
yes it should be.
The clear happens in place and will delete the internal structures.

]]>https://forum.qt.io/post/504145https://forum.qt.io/post/504145Fri, 11 Jan 2019 15:47:44 GMT