Hi,

I have a module A that overloads the '-' operator via its A::oload_minus() subroutine.
And I have a second module B that also overloads the '-' operator via it's own B::oload_minus() subroutine.
Both modules also have their own oload_add, oload_mul, oload_div, oload_mod and oload_pow subroutines that overload the other basic arithmetic operators).

I have constructed the overloading in module A to handle B objects.
But if module B's overloading subroutines are passed a module A object, it is (by my current design) a fatal error. 
use A;
use B;

$A_obj = A->new(16);
$B_obj = B->new(6);

my $n1 = $A_obj - $B_obj; # $n1 is an A object with value 10
my $n2 = $B_obj - $A_obj; # Fatal error

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In the above demo I want $n2 to be an A object, with the value of -10.
That is, I want the A::oload_minus() sub to receive the args ($A_obj, $B_obj, TRUE).
Instead, the B::oload_minus() sub is receiving the args ($B_obj, $A_obj, FALSE) - which is, by my current design, a fatal error since B::overload_minus() does not currently accept A objects.

Is there a way that I can work around this without making any changes to the B module ? (The motivation to not alter module B is simply that I don't want to add more clutter to B unless I need to.)

My module "A" is in fact Math::MPC, and my module "B" is in fact Math::MPFR.

AFTERTHOUGHT: I should point out that the arithmetic overloading in the publicly available versions of Math::MPC don't yet accept Math::MPFR objects. (I've currently implemented this new feature on my local Math::MPC builds only.)

Cheers,
Rob

In reply to A little overloading conundrum by syphilis

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