[Development] Is overriding an existing virtual method 'BC' in Qt 4?

Marc Mutz marc.mutz at kdab.com
Tue Oct 9 12:31:23 CEST 2012

On Wednesday September 26 2012, Thiago Macieira wrote:
> But note that there's one stricter requirement: the forwards compatibility
> that applies within a patch series. Adding this new virtual within the same
> patch series means a new, public symbol, which could get used in
> applications.

What about forward-compatibility if I'm changing a pure-virtual to a mere 
virtual function? AFAIU, pure virtual functions are actually backed by a 
function that prints "pure virtual called" and the aborts. So adding a 
(different) implementation should be ok, even in a patch release[1]?


[1] Though we're talking about 4.8.x here, to which some want to add new API 
(I don't have an opinion, yet).

Marc Mutz <marc.mutz at kdab.com> | Senior Software Engineer
KDAB (Deutschland) GmbH & Co.KG, a KDAB Group Company
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KDAB - Qt Experts - Platform-Independent Software Solutions

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