Function write_encoded 

pub fn write_encoded<'a>(
    path: &Path,
    sample_ty: &str,
    layout: &Layout,
    encs: &[Enc],
    samples: impl IntoIterator<Item = &'a Value>,
) -> Result<u64>

[write], each real leaf in its encoding (encs in storage order, empty for every leaf in f64). The file is version 2 when a real leaf is narrower than f64, and version 1 otherwise, byte for byte what [write] writes. A value that is not a number of its leaf’s encoding is refused (E9004): the file holds the numbers it is given, exactly.