Creates an expression evaluating to the given object with a weak reference.
Once the object is disposed, it will fail to evaluate.
This expression is meant to break reference cycles.
If you want to keep a reference to object, use [ctor@Gtk.ConstantExpression.new].
object to watch
a new GtkExpression
ConstructionException GTK+ fails to create the object.
See Implementation
Creates an expression evaluating to the given object with a weak reference.
Once the object is disposed, it will fail to evaluate.
This expression is meant to break reference cycles.
If you want to keep a reference to object, use [ctor@Gtk.ConstantExpression.new].