rustler_bigint provides support for Erlang's arbitrarily-sized integers.
Add this to Cargo.toml:
toml
[dependencies]
rustler_bigint = { version = "0.1" }
Lets assume that we need to handle integers of variable size. Some might fit
into Rust's i64, but others might not. For example:
elixir
large = Bitwise.bsl(2, 65) # This does not fit into i64, it is an Erlang big integer
In Rust, we can use rustler_bigint::BigInt to pass integer values of
different sizes into a NIF. The type rustler_bigint::BigInt is a newtype
wrapping num_bigint::BigInt and implements std::ops::Deref, so functions
from num_bigint::BigInt can be called directly.
``rust
/// Simply echolarge` back to the caller.
pub fn handlelarge(large: rustlerbigint::BigInt) -> NifResult