Question: is there any other strict explanation for barewords as operands?

I've seen this pattern so many times with modules exporting flags and IIRC even perldocs°, that this discussion is surprising me.

update

°) see last paragraph in chmod

You can also import the symbolic S_I* constants from the Fcntl module:

use Fcntl qw( :mode );
chmod S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH, @executables;
# Identical to the chmod 0755 of the example above.
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Question: is there any other strict explanation for barewords as operands?

Sure, any subs will do - they don't have to be constants:

#!/usr/bin/env perl
use strict;
use warnings;

sub upload      () { rand 50 }
sub getTicket   () { rand 60 }
sub downLoading () { rand 70 }

sub printCLine { print shift }

# Start of bartender1382 code
my $stats = 0;
$stats = upload | getTicket | downLoading;
printCLine ($stats);
# End of bartender1382 code
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---

🦛

> Sure, any subs will do - they don't have to be constants:

you mean any sub with empty prototype which is the way how constants are implemented in constant

see https://perldoc.perl.org/perlsub#Constant-Functions °

and the OP's code still compiles even if your return values are not constant.

Cheers Rolf
_{(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery}

°) NB:

sub FLAG_MASK ()    { FLAG_FOO | FLAG_BAR }

sub FOO_SET () { 1 if FLAG_MASK & FLAG_FOO }
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