anchor.diff:  	t_guard_bifs, t_guard_sequence, t_guard_update,
   	t_guard_receive,t_guard_fun, t_list_comprehension,
   	t_map_sort_literals,
  +	t_map_size,
  +	t_build_and_match_aliasing,
   
   	%% warnings
   	t_warn_useless_build,
  
positive.code: 	t_list_comprehension/1,
  	t_map_sort_literals/1,
  	t_map_size/1,
  
  	%% warnings
  	t_warn_useless_build/1,
  
negative.code:     {'EXIT',{{badmatch,_},_}} = (catch (#{x:=3} = id(#{x=>"three"}))),
      ok.
  
  t_build_and_match_aliasing(Config) when is_list(Config) ->
      M1 = id(#{a=>1,b=>2,c=>3,d=>4}),
      #{c:=C1=_=_=C2} = M1,
      true = C1 =:= C2,
      #{a:=A,a:=A,a:=A,b:=B,b:=B} = M1,
      #{a:=A,a:=A,a:=A,b:=B,b:=B,b:=2} = M1,
      #{a:=A=1,a:=A,a:=A,b:=B=2,b:=B,b:=2} = M1,
      #{c:=C1, c:=_, c:=3, c:=_, c:=C2} = M1,
      #{c:=C=_=3=_=C} = M1,
  
      M2 = id(#{"a"=>1,"b"=>2,"c"=>3,"d"=>4}),
      #{"a":=A2,"a":=A2,"a":=A2,"b":=B2,"b":=B2,"b":=2} = M2,
      #{"a":=_,"a":=_,"a":=_,"b":=_,"b":=_,"b":=2} = M2,
      ok.
  
  t_map_size(Config) when is_list(Config) ->
      0 = map_size(id(#{})),
  