Perl tries to detect indirect object syntax using sometimes subtle hints. I was able to break your example easily on the first try: 

 > perl indobj.pl
Bar
Undefined subroutine &Bar::Foo called at indobj.pl line 10.

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What did I do? I simply moved package Foo to be after package Bar. That way Perl doesn't know that Foo is a package name when it compiles the line of code containing new Foo().

                - tye 
package Bar;

sub new {
    print "Bar\n";
    bless {}
}

sub addFoo {
    my $self = shift;
    $self->{Foo} = new Foo();  # which new gets invoked?
}

package Foo;

sub new {
    print "Foo\n";
    bless {}
}

package main;

my $bar = new Bar();
$bar->addFoo();  # if there's a bug, this should tickle it

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In reply to Re^2: OO style: Placement of "new" (easy) by tye
in thread OO style: Placement of "new" by crenz

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