reject! on ArrayModel doesn't update view

[antoniusostermann]

In my controller I have:

unless page._positions.select{|o| o._row == row && o._col == col}.any? # custom include? method, ids now irreelvant (gitter)
  page._positions << {row: row, col: col} 
else
  page._positions.reject!{|o| o._row == row && o._col == col}
end

(based on what I asked in Gitter)

In my view:

{{page._positions.size}}

On rejecting an element (with bang), the view is not changed. If I use this instead:

page._positions = page._positions.reject{|o| o._row == row && o._col == col}

everything works.