Well, I'd probably help my user by catching some coding mistakes rather than letting them cause strange behavior that they'd have to spend much more time debugging: 

sub method {
    my $self= shift(@_);
    croak 'Usage: $oldVal= $obj->method( $idx [, $newVal ] )',$/
      unless  1 <= @_  &&  @_ <= 2;
    my $i= shift(@_);
    my $old= $self->{B}[$i];
    $self->{B}[$i]= shift(@_)   if  @_;
    return $old;
}

[download]
But I don't like the magic numbers there so I might avoid them at the cost of some duplication but with even better error messages: 
sub method {
    my $self= shift(@_);
    croak 'Missing $idx; usage: $oldVal= $obj->method( $idx [, $newVal
+ ] )',$/
      unless  @_;
    my $i= shift(@_);
    my $old= $self->{B}[$i];
    $self->{B}[$i]= shift(@_)   if  @_;
    croak 'Too many args; usage: $oldVal= $obj->method( $idx [, $newVa
+l ] )',$/
      if  @_;
    return $old;
}

[download]
Then you can remove some duplication with: 
{
    my $usage;
    BEGIN { $usage= '$oldVal= $obj->method( $idx [, $newVal ] )' }

    sub method {
        my $self= shift(@_);
        croak "Missing \$idx; usage: $usage\n"   unless  @_;
        my $i= shift(@_);
        my $old= $self->{B}[$i];
        $self->{B}[$i]= shift(@_)   if  @_;
        croak "Too many args; usage: $usage\n"   if  @_;
        return $old;
    }
}

[download]

        - tye (but my friends call me "Tye")

In reply to (tye)Re: Very very small style question by tye
in thread Very very small style question by Dominus

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