Optimize memory for Int.BigInt()

[hieuvubk]

There are many converts or calculations called Int.BigInt(). Even though the Int structure already contains i *big.Int, new pointer memory is still reallocated. So is there any way that we can reuse the buffer?
I tried returning Int.i directly in my local instead of declaring new memory and here are the benchmark results. However, I'm not sure if direct access poses any danger. Love to hear everyone's opinions.

OLD:
BenchmarkBigInt-16      21329467                47.96 ns/op           24 B/op          3 allocs/op

NEW:
BenchmarkBigInt-16      424790271                2.689 ns/op           0 B/op          0 allocs/op

[alexanderbez]

I think the aim was to avoid mutation of the original Int object. However, we can have two APIs -- one that returns a copy and one that returns the field (allowing mutation).

[hieuvubk]

I think the aim was to avoid mutation of the original Int object. However, we can have two APIs -- one that returns a copy and one that returns the field (allowing mutation).

That would be great! Also do u want me to make a pr?

[alexanderbez]

sure!