use num_bigint::BigInt; use num_traits::cast::FromPrimitive; use num_traits::cast::ToPrimitive; /// Enable big int serialization by providing a `serialize` function pub fn serialize(big_int: &BigInt, serializer: S) -> Result where S: serde::Serializer, { serde::Serialize::serialize( &big_int .to_i64() .ok_or_else(|| serde::ser::Error::custom("expected a i64-sized bignum"))?, serializer, ) } /// Enable big int deserialization by providing a `deserialize` function pub fn deserialize<'de, D>(deserializer: D) -> Result where D: serde::Deserializer<'de>, { let x: i64 = serde::Deserialize::deserialize(deserializer)?; Ok(BigInt::from_i64(x) .ok_or_else(|| serde::de::Error::custom("expected a i64-sized bignum"))?) }