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Re: Lambda support in MenuBar [message #46611 is a reply to message #46599]

Sat, 11 June 2016 11:23

Klugier
Messages: 1099
Registered: September 2012
Location: Poland, Kraków

Senior Contributor

Hello Mirek - Now more serious,

I tried to integrated new lambda callback with ide New file menu - but there is a problem. Here is my new code:

void WorkspaceWork::NewMenu(Bar& bar)
{
	bar.Add("File", CtrlImg::File(), THISBACK2(NewPackageFile, "New file", ""));
	bar.Add("Separator", THISBACK(AddSeparator))
		.Help("Add text separator line");
	
	bar.Separator();
	for (int i = 0; i < categories.GetCount(); i++) {
                // Lambda in place - as argument
		bar.Add(categories.GetKey(i), [&, i](Bar& subBar) {
			for (FileType& fileType : categories[i]) {
				String name = fileType.GetName();
				String extension = fileType.GetExtension();
				
				if (fileType.IsSeparator())
					subBar.Separator();
				else
					subBar.Add(name, fileType.GetImage(), THISBACK2(NewPackageFile, "New " + name, extension));
			}
		});
	}
}

And i have got following compilation issue:

/home/klugier/upp/uppsrc/Core/Callback.h: In instantiation of 'Res Upp::Function<Res(ArgTypes ...)>::Wrapper<F>::Execute(ArgTypes ...) [with F = WorkspaceWork::NewMenu(Upp::Bar&)::<lambda(Upp::Bar&)>; Res = void; ArgTypes = {}]
    ':
/home/klugier/upp/uppsrc/ide/UppWspc.cpp:1238:1:   required from here
/home/klugier/upp/uppsrc/Core/Callback.h:15:60: error: no match for call to '(WorkspaceWork::NewMenu(Upp::Bar&)::<lambda(Upp::Bar&)>) ()'
   virtual Res Execute(ArgTypes... args) { return fn(args...); }
                                                            ^
/home/klugier/upp/uppsrc/ide/UppWspc.cpp:931:51: note: candidate: WorkspaceWork::NewMenu(Upp::Bar&)::<lambda(Upp::Bar&)>
   bar.Add(categories.GetKey(i), [&, i](Bar& subBar) {
                                                   ^
/home/klugier/upp/uppsrc/ide/UppWspc.cpp:931:51: note:   candidate expects 1 argument, 0 provided
In file included from /home/klugier/upp/uppsrc/Core/Core.h:293:0,
                 from /home/klugier/upp/uppsrc/Esc/Esc.h:4,
                 from /home/klugier/upp/uppsrc/ide/Core/Core.h:4,
                 from /home/klugier/upp/uppsrc/ide/Common/Common.h:4,
                 from /home/klugier/upp/uppsrc/ide/ide.h:4,
                 from /home/klugier/upp/uppsrc/ide/UppWspc.cpp:1:
/home/klugier/upp/uppsrc/Core/Callback.h:15:60: error: return-statement with a value, in function returning 'void' [-fpermissive]
   virtual Res Execute(ArgTypes... args) { return fn(args...); }

Is that problem here that bar lambda is created in THISBACK method?

Sincerely,
Klugier

U++ - one framework to rule them all.

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