[webkit-dev] Does someone know how to fix WTF::Function on Windows

[Chris Dumez]

I seem to remember I fixed it last time by calling the WTF::Function constructor explicitly.

Chris Dumez

> On Jul 15, 2017, at 9:14 AM, Yusuke SUZUKI <utatane.tea at gmail.com> wrote:
> 
> I'm not 100% confident, but can you try it `&testFunction` instead?
> 
> Regards,
> Yusuke Suzuki
> 
>> On Sun, Jul 16, 2017 at 1:13 AM, Darin Adler <darin at apple.com> wrote:
>> Hi folks.
>> 
>> On Windows, WTF::Function doesn’t quite work right. Code that is something like this:
>> 
>>     void addCallback(WTF::Function<void()>&&);
>> 
>>     void testFunction()
>>     {
>>         // ...
>>     }
>> 
>>     void addTestFunction()
>>     {
>>         addCallback(testFunction);
>>     }
>> 
>> Leads to errors like this:
>> 
>>     error C2664: 'void addCallback(WTF::Function<void (void)> &&)': cannot convert argument 1 from 'void (__cdecl *)(void)' to 'WTF::Function<void (void)> &&'
>>     note: You cannot bind an lvalue to an rvalue reference
>> 
>> The problem might have something to do with cdecl vs. stdcall functions, but I am not sure that is the problem. It could be some other problem with how WTF::Function is written. Or it might even be a bug in the Visual Studio compiler. Since I don’t have a Windows machine myself, I was trying to use EWS to figure this out but that was slow. Then I tried using http://webcompiler.cloudapp.net but I could not reproduce any error there when I pasted in cut down code; it just compiled fine.
>> 
>> Is there someone who knows how to fix this?
>> 
>> Another way to put this is: We want to take off the explicit WTF::Function conversions in functions like canUseWithReason in SimpleLineLayout.cpp, Page::Page in Page.cpp, and Worker::Worker in Worker.cpp and have it still compile and work on Windows. Other platforms seem to compile fine without the explicit WTF::Function.
>> 
>> — Darin
>> _______________________________________________
>> webkit-dev mailing list
>> webkit-dev at lists.webkit.org
>> https://lists.webkit.org/mailman/listinfo/webkit-dev
> 
> _______________________________________________
> webkit-dev mailing list
> webkit-dev at lists.webkit.org
> https://lists.webkit.org/mailman/listinfo/webkit-dev
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-dev/attachments/20170715/bee429cb/attachment.html>