[Development] Qt 5 types under consideration for deprecation / removal in Qt 6

Olivier Goffart olivier at woboq.com
Wed May 29 17:30:10 CEST 2019

On 29.05.19 17:17, Mutz, Marc via Development wrote:
> But of course, that's a fallacy, because as soon as Qt internally uses said 
> inline functions, every use of them by the user with a different STL is an ODR 
> violation and therefore UB. So, again AFAICT, the decision was that we can use 
> std types in the API now, even when not inline.
> Someone correct me if I'm wrong.

I believe you are right. But binary compatibility, as a whole, is a ODR 
violation, and therefore is UB. (Unless we really do not touch any of the 
existing class in a public header files, not even to add a typedef or a method 
in them)

In practice, however, it works. Same as changing the stdlib, because they also 
keeps binary compatibility across version and libc++ and libstdcpp are in 
different namespace.


Woboq - Qt services and support - https://woboq.com - https://code.woboq.org

More information about the Development mailing list