But, I do get what you mean. In the docs for 5.10 I just read about the new lexical $_ that locally overrides the global of the same name.

I personally believe that I can now say() it: I've been waiting for this for quite a lot of time:

C:\temp>cat 510.pl
#!/usr/bin/perl

use 5.010;
use strict;
use warnings;

my @x=1..3;

say for map { sub {$_} } @x;
say for map { my $n=$_; sub {$n} } @x;

{
    my $_;
    say for map { sub {$_} } @x;
}

__END__

C:\temp>\programmi\perl510\bin\perl 510.pl
CODE(0x184fcbc)
CODE(0x184fcbc)
CODE(0x184fcbc)
CODE(0x229dbc)
CODE(0x229e6c)
CODE(0x182a2fc)
CODE(0x229dbc)
CODE(0x182a0cc)
CODE(0x182a14c)
[download]

Update: I also notice in the delta manpage the remark that "substr() lvalues are no longer fixed-length." I believe it was you who talked (to me) about substr() lvalues in the first place, and about the fixed length limitation.