Function pair 

pub fn pair<I, O1, O2, E, F, G>(first: F, second: G) -> impl FnMut(I)
where
    E: ParseError<I>,
    F: Parser<I, O1, E>,
    G: Parser<I, O2, E>,

Available on crate features crypto and std only.

Gets an object from the first parser, then gets another object from the second parser.

Arguments

• first The first parser to apply.
• second The second parser to apply.

use nom::sequence::pair;
use nom::bytes::complete::tag;

let mut parser = pair(tag("abc"), tag("efg"));

assert_eq!(parser("abcefg"), Ok(("", ("abc", "efg"))));
assert_eq!(parser("abcefghij"), Ok(("hij", ("abc", "efg"))));
assert_eq!(parser(""), Err(Err::Error(("", ErrorKind::Tag))));
assert_eq!(parser("123"), Err(Err::Error(("123", ErrorKind::Tag))));