use 5.010;

sub my_sub (&) {
    my $code = shift;
    local $_ = '1234';
    $code->();
}

my_sub { say };

given ("test") {
    when ("test") {
        my_sub { say };
    }
}

##</code><code>##

1234
test

##</code><code>##

use 5.010;

sub my_sub (&) {
    my $code = shift;
    local $_ = '1234';
    $code->();
}

my_sub { say };

sub my_sub2 {
    my_sub { say };
}

given ("test") {
    when ("test") {
        my_sub2();
    }
}