Macro collection 

collection!() { /* proc-macro */ }

Generate an anonymous struct which implements kas::Collection

Syntax

Collection :
   collection! [ Items^? ]

Items :
   (Item ,)^* Item ,^?

In this case, Item may be:

• A string literal (interpreted as a label widget), optionally followed by any of the following method calls: align, pack, with_stretch, with_margin_style
• An expression yielding an object implementing Widget<Data = _A>

In case all Item instances are a string literal, the data type of the collection! widget will be (); otherwise the data type of the widget is _A where _A is a generic type parameter of the widget.

For example usage, see List.