[Qt5-feedback] C++ api to use for UI in addition to QML

[Craig.Scott at csiro.au]

On 25/05/2011, at 1:49 AM, Konstantin Tokarev wrote:

24.05.2011, 19:32, "Charley Bay" <charleyb123 at gmail.com<mailto:charleyb123 at gmail.com>>;:

 I understand binary compatibility for "minor dot" releases (e.g., between 4.7.1 and 4.7.2), but see no reason for binary compatibility for any other release.

What about LSB?

To be more explicit about this, Qt is part of the LSB (Linux Standards Base). One of the obligations of being part of the LSB is that Qt must preserve binary compatibility. The LSB defines the binary interfaces that must appear (right down to the mangled names in the libraries) and the layout of data structures also. It even defines things that must be in the headers. These are very precise requirements and they are a prime example of why the Qt guys need to be obsessed with binary compatibility.

To some extent, the LSB is (or aims to be) for linux developers what a Visual Studio runtime version is for Windows developers, ie a binary target they can build their packages against and have the assurance that it should run fine on any compliant system. Under Windows, you would require a particular runtime redistributable to be installed. Under linux, you would require the linux distribution to provide the relevant LSB dependency package to be installed. The result is the same for both platforms. I'll make a separate follow-up post on this shortly.

If you think that the LSB isn't important, note that all major linux distributions aim to have themselves certified against it and indeed they are doing so (see what happened with the raft of LSB 4.0 certifications late last year). It takes resources for them to do this, but they consider it sufficiently important that they do it and have done so for some years.

--
Dr Craig Scott
Computational Software Engineering Team Leader, CSIRO (CMIS)
Melbourne, Australia