There does not seem to be a meaningful distinction in Perl. The return value is not intimately connected to the following assignment. Consider this snippet:

use Data::Dump;

my $foo = 7;
sub bar :lvalue { $foo }
sub baz :lvalue { bar }

dd $foo, bar(), baz();
baz = 9;

for (baz) {
    dd $foo;
    $_ = 4;
    dd $foo;
}
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As you can see, $foo is passed around (by reference), but there is no telling if and where it is going to be assigned.