Function from_slice 

pub fn from_slice<'de, T: Deserialize<'de>>(
    bytes: &'de [u8],
) -> Result<T, Error>

Deserializes the records of a byte slice.

Fields which are not UTF-8 are passed on as bytes.

use std::collections::BTreeMap;

let rows: Vec<BTreeMap<String, u32>> =
    deser_csv::from_slice(b"a,b\n1,2\n").unwrap();
assert_eq!(rows[0]["b"], 2);