Method try_from_fields

arrow-schema/src/fields.rs:517–535

Create a new [`UnionFields`] from a collection of fields with automatically assigned type IDs starting from 0. The type IDs are assigned in increasing order: 0, 1, 2, 3, etc. This is the non-panicking version of [`UnionFields::from_fields`]. See # Errors Returns an error if the number of fields exceeds 127 (the maximum value fo

(fields: F)

    /// assert!(result.is_err());
    /// ```
    pub fn try_from_fields<F>(fields: F) -> Result<Self, ArrowError>
    where
        F: IntoIterator,
        F::Item: Into<FieldRef>,
    {
        let mut out = Vec::with_capacity(i8::MAX as usize + 1);

        for (i, field) in fields.into_iter().enumerate() {
            let id = i8::try_from(i).map_err(|_| {
                ArrowError::InvalidArgumentError(
                    "UnionFields cannot contain more than 128 fields".into(),
                )
            })?;

            out.push((id, field.into()));
        }

        Ok(Self(out.into()))
    }

    /// Return size of this instance in bytes.
    pub fn size(&self) -> usize {