[Development] MSVC not inlining QRect inline functions (anymore?)

[Marc Mutz]

On 08.06.26 00:02, Thiago Macieira wrote:

On Sunday, 7 June 2026 08:48:33 Pacific Daylight Time Christian Ehrlicher via
Development wrote:


I recently found out that none of the QRect inline functions are inlined
by msvc no matter what compiler options I pass. Tested with recent cl
(19.51.36244) but also saw this with older msvc2022 compilers.
Is this known and should/can we do something against this?


Get a better compiler.

MSVC is well-known for *not* inlining functions that are dllimported, if they
are anything except the most trivial.

Christian said that QRectF doesn't have the problem, and fingered QCheckedInt as the potential culprit.

I think you may both be right. QRectF is also wholesale-exported, but the QCheckedInt change pushed QRect into "anything but most trivial" mode.

Aaaand another entry into the ever-growing list of "never wholesale-export a non-polymorphic rule" failures (https://wiki.qt.io/Things_To_Look_Out_For_In_Reviews#Value_Classes Item 6).

Thanks,
Marc

PS: from a recent Claude Opus conversation:

The non-export rule for non-polymorphic classes has essentially no legitimate exception — the only reason to whole-class export one is laziness, and it strictly costs you. The closest thing is a non-polymorphic class you're exporting every member of anyway, where the wholesale macro is just shorthand; even then it silently re-emits inlines and invites C4251, so prefer the explicit member exports.


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Marc Mutz <marc.mutz at qt.io><mailto:marc.mutz at qt.io> (he/his)
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