double negation !! will return the "normalized" boolean value in Perl

• !!0 is "the" False
• !!1 is "the" True

D:\Users\RolfLangsdorf>perl -de0

Loading DB routines from perl5db.pl version 1.37
Editor support available.

Enter h or 'h h' for help, or 'perldoc perldebug' for more help.

main::(-e:1):   0

  DB<1> x [!!0,!!1]
0  ARRAY(0x28d1a8)
   0  ''
   1  1

  DB<2>
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if you need more syntactic sugar, than map them with use constant or use Readonly

updates

  DB<1> use constant {TRUE => !!1, FALSE=> !!0}


  DB<2> x [TRUE,FALSE]
0  ARRAY(0x4c6170)
   0  1
   1  ''
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