Function numeric_type

src/validation.rs:346–382

(deserializer: D)

}

fn numeric_type<'de, D>(deserializer: D) -> std::result::Result<TryParse<u64>, D::Error>
where
    D: Deserializer<'de>,
{
    struct NumericType(PhantomData<fn() -> TryParse<u64>>);

    impl Visitor<'_> for NumericType {
        type Value = TryParse<u64>;

        fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
            formatter.write_str("A NumericType that can be reasonably coerced into a u64")
        }

        fn visit_u64<E>(self, value: u64) -> std::result::Result<Self::Value, E>
        where
            E: de::Error,
        {
            Ok(TryParse::Parsed(value))
        }

        fn visit_f64<E>(self, value: f64) -> std::result::Result<Self::Value, E>
        where
            E: de::Error,
        {
            if value.is_finite() && value >= 0.0 && value < (u64::MAX as f64) {
                Ok(TryParse::Parsed(value.round() as u64))
            } else {
                Err(serde::de::Error::custom("NumericType must be representable as a u64"))
            }
        }
    }

    match deserializer.deserialize_any(NumericType(PhantomData)) {
        Ok(ok) => Ok(ok),
        Err(_) => Ok(TryParse::FailedToParse),
    }
}

#[cfg(test)]
mod tests {