`BigInt(new Amount(bigint))` roundtrip.

[acutmore]

BigInt(value) currently calls value[Symbol.toPrimitive]("number").

If that remains it means an amount created from a bigint could lose data if it was passed to BigInt.

Ideas:

• This is OK
• Throw if BigInt() is passed an amount
• Get a bigint similar to Amount.prototype.toBigInt()

[ljharb]

We could also expand ToPrimitive to allow a hint of "bigint".

[eemeli]

Or we could add a specific check for Amount in BigInt(value) before the ToPrimitive() call.

[jessealama]

Or we could add a specific check for Amount in BigInt(value) before the ToPrimitive() call.

This is currently what Decimal does: http://tc39.es/proposal-decimal/#sec-bigint-constructor-number-value

[jessealama]

We could also expand ToPrimitive to allow a hint of "bigint".

I like this idea. Having only string and number as options reflects an older time; we've had BigInts for a while now, so it should be safe to embrace them. What's your sense of how spec editors and implementors might feel about this approach?