$ perl -Mstrict -E 'use warnings; my $x; say $x+1'
Use of uninitialized value $x in addition (+) at -e line 1.
1
$ perl -Mstrict -E 'use warnings (); my $x; say $x+1'
1

##</code><code>##

$ perl -Mstrict -E 'use if 1==1, warnings => (); my $x; say $x+1'
Use of uninitialized value $x in addition (+) at -e line 1.
1

##</code><code>##

$ perl -Mstrict -E 'BEGIN { require warnings if 1==1 } my $x; say $x+1'
1

##</code><code>##

$ perl -MO=Deparse,-p -e 'use if 1==1, warnings => ()'
use if (1, 'warnings', ());
-e syntax OK
$ perl -Mstrict -E 'use if (1, "warnings", ()); my $x; say $x+1'
Use of uninitialized value $x in addition (+) at -e line 1.
1

##</code><code>##

$ perl -wMstrict -E 'use open ()'
$ perl -wMstrict -E 'use if 1==1, open => ()'
open: needs explicit list of PerlIO layers at -e line 1.
BEGIN failed--compilation aborted at -e line 1.
$ perl -wMstrict -E 'use feature ()'
$ perl -wMstrict -E 'use if 1==1, feature => ()'
No features specified at -e line 1.
BEGIN failed--compilation aborted at -e line 1.
$ perl -wMstrict -E 'use List::Util ()'
$ perl -wMstrict -E 'use if 1==1, List::Util => ()'
Bareword "List::Util" not allowed while "strict subs" in use at -e line 1.
Execution of -e aborted due to compilation errors.

##</code><code>##

package if;

$VERSION = '0.0606';

sub work {
  my $method = shift() ? 'import' : 'unimport';
  unless (@_ >= 2) {
    my $type = ($method eq 'import') ? 'use' : 'no';
    die "Too few arguments to '$type if' (some code returning an empty list in list context?)"
  }
  return unless shift;		# CONDITION

  my $p = $_[0];		# PACKAGE
  (my $file = "$p.pm") =~ s!::!/!g;
  require $file;		# Works even if $_[0] is a keyword (like open)
  my $m = $p->can($method);
  goto &$m if $m;
}

sub import   { shift; unshift @_, 1; goto &work }
sub unimport { shift; unshift @_, 0; goto &work }

1;

##</code><code>##

$ perl -wMstrict -E '@_ = (1, 2, ()); say 0+@_'
2

##</code><code>##

use if CONDITION, MODULE => ();

##</code><code>##

use if CONDITION, MODULE;