Re^2: Why are "a ||= b" and "a = a || b" different?

It looks like there really is a difference in the calling context:

#!/usr/bin/perl

use Carp;

my $ret;

undef $ret;
($ret) ||= foo();
warn "ret is $ret";

undef $ret;
($ret) = $ret || foo();
warn "ret is $ret";

sub foo
{
  carp "Want " . (wantarray ? "array" : "scalar");
  (1,2);
}
[download]

outputs:

Want scalar at t3 line 17
        main::foo() called at t3 line 8
ret is 2 at t3 line 9.
Want array at t3 line 17
        main::foo() called at t3 line 12
ret is 1 at t3 line 13.
[download]

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Comment on Re^2: Why are "a \|\|= b" and "a = a \|\| b" different? Select or Download Code

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Re^3: Why are "a \|\|= b" and "a = a \|\| b" different? by Anonymous Monk on Mar 05, 2007 at 10:07 UTC
void is false `my $w = wantarray; $w = defined $w ? ($w ? 'list' : 'scalar') : 'void'; carp "wantarray : $w ";` [download]	[reply] [d/l]
Re^4: Why are "a \|\|= b" and "a = a \|\| b" different? by diotalevi (Canon) on Mar 05, 2007 at 15:48 UTC
Why copy the value of wantarray into a temporary? You're just adding visual and other overhead. ⠤⠤ ⠙⠊⠕⠞⠁⠇⠑⠧⠊	[reply]