Give local higher precedence
>perl -le"$x=2; { (local $x)=$x; print $x; $x=3; print $x } print $x"
2
3
2

Give assignment higher precedence
>perl -le"$x=2; { local ($x=$x); print $x; $x=3; print $x } print $x"
2
3
3   <-- XXX