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]

--
sgifford's Web page

In reply to Re^2: Why are "a ||= b" and "a = a || b" different? by sgifford
in thread Why are "a ||= b" and "a = a || b" different? by saintmike

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