[Development] Proposal: Deprecating platforms in Qt 5.6 that don't support lambda

[Olivier Goffart]

On Wednesday 13. May 2015 09:45:30 Matthew Woehlke wrote:
> On 2015-04-30 16:04, Matthew Woehlke wrote:
> > On 2015-02-20 14:42, Thiago Macieira wrote:
> >> On Friday 20 February 2015 12:53:24 Matthew Woehlke wrote:
> >>>   for (auto const i : qtEnumerate(map))
> >>> 
> >>> Maybe it would be nice for Qt to provide one or both of these?
> >> 
> >> Sounds easy enough. Want to give it a try?
> > 
> > I *finally* got permission to share this. Sorry it took so long.
> > 
> > The attached code, excluding the copyright notices, is hereby placed
> > into the Public Domain. Permission is also granted to use the attached
> > code under either the BSD license, as stated in the files themselves, or
> > pursuant to Kitware's CLA with Qt.
> > 
> > It is my hope that this is useful to other people. (Also that the first
> > one finds its way into STL eventually :-), though that's a bit OT for
> > here.)
> > 
> > These are both C++11 code. At minimum, they'll need brace-initialization
> > changed to parentheses-initialization in order to build in C++03 mode.
> > However, qtIndexRange also uses trailing return type specification, and
> > I'm not sure it's possible to avoid that without losing type deduction,
> > which sort-of defeats the purpose. There are also lots of elided type
> > specifiers, though those are easy enough to add.
> > 
> > Personally, I wouldn't consider it a terrible loss if these were only
> > available in C++11-or-later mode, since they're intended to be used with
> > range-based for.
> > 
> >> Note that this should also work for foreach:
> >> 	foreach (const auto i, qtEnumerate(map))
> > 
> > I'm not sure if it will or not; it was designed to work in range-based
> > for, i.e. it supplies begin() and end(). I'm not sure if that's enough
> > to automagically work in Q_FOREACH.
> > 
> > Thiago, do you want me to take another look at integrating these into Qt
> > proper, or do you have it in hand?
> 
> Ping?

If you want to integrate something to Qt you need to upload the contribution 
through gerrit.

I'm afraid your solution is not working with temporaries containers.

-- 
Olivier 

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