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lp1845837: Speed up purging of tracks #2393
lp1845837: Speed up purging of tracks #2393
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Why not const QList& ? A copy by value increases the shared counter, which requires qt:as_const() in range based loops to be efficient.
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Because a local, writable copy is need for sorting. First line of the function body.
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The QList is actually not shared, but moved into this function. The caller never accesses it again after calling the function. The copy happens, because instead of move semantics Qt relies on implicit sharing.
I could add a
std::move
at the caller's site, because QList has a move constructor. This should eliminate the temporary copy.There was a problem hiding this comment.
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Ah I see, thank you for explaining.
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I omitted to use
std::move
in the first place because I was recently told not to use it in Qt code ;) What I definitely won't do is checking each and every Qt class before using it. I prefer to use it if it is semantically correct, whether it is supported or not.