use strict;
use warnings;
use Contextual::Return;
use Carp;

while (foo()) { last; }
while (my $x = foo()) { last; }
if (foo()) { }
if (my $z = foo()) { }

sub foo {
  return
    BOOL          { carp "BOOL"; 1; }
    SCALAR        { carp "SCALAR"; 1; }
  ;
}
__END__
BOOL at ./cr line 6
BOOL at ./cr line 7
BOOL at ./cr line 8
BOOL at ./cr line 9