Function encode_map 

pub fn encode_map<'a, K, V>(
    map: impl Iterator<Item = (&'a K, &'a V)>,
    buf: &mut [u8],
) -> Result<usize, EncodeError>
where
    K: Varint + 'a,
    V: Varint + 'a,

Encodes a map of entries as varints and writes them to the buffer.

Returns the total number of bytes written to the buffer.

Example

use varing::{Varint, decode_map, encoded_map_len, encode_map};
use std::collections::HashMap;

let values = (0..1024u64).map(|v| (v, v)).collect::<HashMap<_, _>>();

let encoded_len = encoded_map_len(values.iter());
let mut buf = vec![0; encoded_len];

let bytes_written = encode_map(values.iter(), &mut buf).unwrap();
assert_eq!(bytes_written, encoded_len);

let (readed, decoded) = decode_map::<_, _, HashMap<u64, u64>>(&buf).unwrap();

assert_eq!(decoded, values);
assert_eq!(readed, buf.len());