[Interest] why does Qt prefer to return QList over QVector?

[Daniel França]

is QVector faster even for sequential access?
On Tue 27 Jan 2015 at 09:42 Mark Gaiser <markg85 at gmail.com> wrote:

> On Tue, Jan 27, 2015 at 8:56 AM, Felix morack <felixover at gmail.com> wrote:
>
>> hello,
>>
>>
>> i recently gained a small, but considerable performance boost by
>> switching out QList for QVector in some legacy code. This is hindered by
>> the fact that Qt itself often returns QList, eg with QMap::values().
>>
>>
>> Is there a reason for this? Why arent QVectors used?
>>
>>
>> A somewhat related question, why is there no QList::reserve()? I guess i
>> see how that function might not make much sense from an algorithmic pov,
>> but shouldnt it at least be there as a NoOp to make it easy switching
>> between data structures?
>>
>>
>> best regards,
>>
>> As far as i know this is for historic reasons. QList used to be faster
> then QVector (someone, please correct me if i'm wrong) in the old days, but
> nowadays (Qt5 era) they prefer QVector over QList. It is as fast or faster
> then QList in nearly every situation. I vaguely remember there being one
> exception where QList was faster, but i don't know the exception anymore.
>
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