source: vendor/perl/5.8.8/t/op/not.t

#!./perl -w

BEGIN {
    chdir 't' if -d 't';
    @INC = '../lib';
    require './test.pl';
}

plan tests => 16;

# not() tests
pass() if not();
is(not(), 1);
is(not(), not(0));

# test not(..) and !
is(! 1, not 1);
is(! 0, not 0);
is(! (0, 0), not(0, 0));

# test the return of !
{
    my $not0 = ! 0;
    my $not1 = ! 1;

    no warnings;
    ok($not1 == undef);
    ok($not1 == ());

    use warnings;
    ok($not1 eq '');
    ok($not1 == 0);
    ok($not0 == 1);
}

# test the return of not
{
    my $not0 = not 0;
    my $not1 = not 1;

    no warnings;
    ok($not1 == undef);
    ok($not1 == ());

    use warnings;
    ok($not1 eq '');
    ok($not1 == 0);
    ok($not0 == 1);
}