Bug 431789

Summary:	False positive with -clazy-inefficient-qlist
Product:	[Developer tools] clazy	Reporter:	Roman <dismine>
Component:	general	Assignee:	Unassigned bugs <unassigned-bugs-null>
Status:	RESOLVED INTENTIONAL
Severity:	normal	CC:	smartins
Priority:	NOR
Version First Reported In:	unspecified
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Roman 2021-01-18 16:36:31 UTC

Clazy shows an error about inefficient use of QList in the case of QList<T> QMap::values() method.


STEPS TO REPRODUCE
1. Call QList<T> QMap::values() for type with size 16 bytes. 

Because there is no values() method with QVector it should probably skip this case.

Comment 1 Sergio Martins 2021-02-07 13:12:35 UTC

Calling values QMap::values() just makes it worse, as it allocates a temporary container, see README-container-anti-pattern.md.

Ofc, people will always find cases where "but here it's useful for me!", for that reason, inefficient-qlist is disabled by default, and there's inefficient-qlist-soft.

Anyway, no point on spending our weekend around this since it's already a non-issue in Qt 6, where this check doesn't make sense anymore. Any effort spend here will be wasted in the long run.