This class is used to provide "low-priority" implicits for the types defined within CanHold.
CanHold
These implicits are not favoured equally to the implicits defined within CanHold and this means that Scala will not have any ambiguous implicit errors.
4.0.0
Evidence that BigInt can store (at least) 64 bits of data.
BigInt
long_64 is prioritised for implicit selection over this.
long_64