##
use warnings '+mixedtypes';
@a=(1,2);
@b=(@a, [3,4]); #would give warning!
##
##
use warnings '+mixedtypes';
@a=(1,2);
$a[1]=[3,4]; #warning - mixed type assigned to @a
$a[1]=($)[3,4]; #would store the ref into a scalar-typed target without warning