[swift-evolution] Custom didSet methods

[James Campbell]

When declaring a collection, it would be nice to have a way of knowing when
an item is set/added and removed.

For example you could trigger a layer to be added to the layer hiearchy.

var shapeLayers: [CAShapeLayer] {

didAdd(item) {
 addSubLayer(item)
}

willRemove(item){
 item.removeFromSuperlayer()
}
}

-- 
 Wizard
james at supmenow.com
+44 7523 279 698
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