So, is it feasible?

update

Looks good to me, even with core modules. =)

use v5.12;                              # enable say & strict
use warnings;

{
    package MySay;

    use Data::Dump qw/pp dd/;
    use Carp;
    require Tie::Handle;

    our @ISA = qw(Tie::Handle);


    sub TIEHANDLE {
        #carp pp '\@_: ', \@_;
        bless \ my $i, shift
    }

    sub PRINT {
        my $self = shift;
        print STDOUT "$_" for @_
    }

    sub new {
        my $self = shift;

        open my $fh, ">&STDOUT";
        tie *$fh, 'MySay';
        return($fh);
    }

    # sub DESTROY {
    #     print STDOUT "DESTROY";
    #     # my $self = shift;
    #     select(STDOUT);
    # }
}



{
    package main;

    # ----  test vars
    $_='$_';
    my @a = map { "\$a[$_]" } 0..2;
    my @b;


    {

        select MySay->new();

        say;

        say @b;

        say @a;

        select(STDOUT)
    }


    say "AF","TER"
}
[download]

C:/Strawberry/perl/bin\perl.exe -w d:/tmp/pm/tie_handle.pl 
$_
$a[0]
$a[1]
$a[2]
AFTER
[download]

with some effort it might even be possible to automatically destroy the selection at end of scope, such that one only needs to write MySay->select() once without any further need for visible select

But I got tired and wanted to get it done. :)

Looks good to me, even with core modules. =)

Yes, Tie::Handle and Tie::StdHandle aren't too bad, they're just not necessarily consistent across Perl versions. For example, Tie::StdHandle::BINMODE didn't handle a "layer" argument until I patched it (this fix wasn't included until v5.32.0). Also, its sub WRITE still doesn't return the length of the data written, like syswrite normally would. Tie::Handle::Base works the same all the way down to Perl 5.8.1 (of course I have lots of tests :-) ).