Hi,

I recently wanted to overload '*' with one of my class which can accept external multiplication with bigints.

In other words, I wanted to do something like: 

my $obj = new My::Custom::Object;
use bigint;
my $mult = 2**100 *  $obj;

[download]

I realised that overloading '*' inside My::Custom::Object would not be enough as the class resolution would first process '*' inside Math::BigInt if the number is the first operand.

So I thought I should directly overload '*' inside Math::BigInt. I guess I can do that even if this class is not "mine", right?

package Math::BigInt;
use overload '*' =>
sub {
    if (ref $_[1] eq 'My::Custom::Object') {
         $_[1]->MultiplyByInt($_[0]);
    }
    else {
         $_[0]->bmult($_[1]);
    }
}

[download]

I'm not sure this is a good solution, though. My concern is about using 'bmult' instead of '*'. I doubt bmult will behave correctly if something else than a BigInt is provided as a second operand.

I thought about creating a child class of Math::BigInt so '*' can fallback to parent '*' when necessary but then I'll have to explicitely bless my integers which would be annoying.

So, how should I do this right?

In reply to Overloading multiplication involving BigInt by grondilu

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