[Interest] Prevent tabbing of Qt application on macOS Sierra

[René J. V. Bertin]

Jake Petroules wrote:


> This was mostly for illustration. OK, let me reformulate... don't actually
> include Qt private headers, but add an equivalent of the __builtin_available
> shim in your own codebase if you need to build with Xcode older than 9.
> 
> See https://codereview.qt-project.org/#/c/206346/

Why not simply provide the shims in a header that doesn't also introduce 
dependencies on a specific Qt version or build? Could easily be part of 
QtMacExtras, for instance. Or better yet, provide a convenience wrapper that 
removes the need for using both a preprocessor macro AND a feature that pretends 
not to be a compile-time conditional (and which probably chokes other 
compilers).

But if I understand correctly the new feature should be available in any clang 5 
build? Must be why they did a major version bump then... 8-)

R.