This isn't a definite solution, but I guess it could help sometimes. 

package Bloodnok;

sub new { bless {}, shift }
sub call {
    my ( $self, $position ) = @_;

    my $wa = wantarray;
    if ( $wa ) {
        print "$position: list\n";
    }
    elsif ( defined $wa ) {
        print "$position: scalar\n";
    }
    else {
        print "$position: void\n";
    }

    return $self;
}
package main;

my $yo_sup_b = Bloodnok->new();
$yo_sup_b->call( 'void start' )
         ->call( 'void mid' )
         ->call( 'void end' );
scalar $yo_sup_b->call( 'scalar start' )
                ->call( 'scalar mid' )
                ->call( 'scalar end' );
() = $yo_sup_b->call( 'list start' )
              ->call( 'list mid' )
              ->call( 'list end' );
__END__
void start: scalar
void mid: scalar
void end: void
scalar start: scalar
scalar mid: scalar
scalar end: scalar
list start: scalar
list mid: scalar
list end: list

[download]

Long story short, wantarray will always show a scalar context for calls before the end of a chain, but it shows the original context at the end of the chain. If your chain is in a scalar context anyway, that doesn't help at all, but in the other two contexts you can tell you must be at the end.

In reply to Re: Determination of chained method call context by kyle
in thread Determination of chained method call context by Bloodnok

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