to prove tybaldt's point that Unary "+" has no effect whatsoever

#!/usr/bin/perl -w
use warnings;
use strict;

# --------------------
#  force context
# --------------------
sub VOID (&) {
  print "VOID:\t";
  $_[0]->();
  return;
}

sub LIST (&) {
  print "LIST:\t";
  () = $_[0]->();
  return;
}

sub SCALAR (&) {
  print "SCALAR:\t";
  scalar $_[0]->();
  return;
}

# --------------------
# tests
# --------------------

sub ctxt {
   unless (defined wantarray) {
      print "is void\n";
   } elsif (wantarray) {
      print "is list\n";
   } else {
      print "is scalar\n";
   }
}

SCALAR { ctxt };
SCALAR { +(ctxt) };           # u+ no effect

LIST { ctxt };
LIST { +(ctxt) };             # u+ no effect

VOID { ctxt };
VOID { +(ctxt) };;            # u+ no effect

#  BUT

LIST { 0+(ctxt) };            # forcing scalar context

[download]

SCALAR:    is scalar
SCALAR:    is scalar
LIST:    is list
LIST:    is list
VOID:    is void
VOID:    is void
LIST:    is scalar

[download]

(code stolen from older post)

Cheers Rolf
(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery FootballPerl is like chess, only without the dice

In reply to Re: u+ fails to force scalar context to empty list assignment: +( () = ... ) by LanX
in thread u+ fails to force scalar context to empty list assignment: +( () = ... ) by rsFalse

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