Function parse 

pub fn parse(input: &str) -> Result<Version<'_>, ParseError>

Parses a SemVer version string.

use semver::parse;

let v = parse("1.0.0").unwrap();
assert_eq!(v.major, 1);
assert_eq!(v.to_string(), "1.0.0");

let v = parse("1.0.0-alpha.1+build.123").unwrap();
assert_eq!(v.to_string(), "1.0.0-alpha.1+build.123");

assert!(parse("01.2.3").is_err());
assert!(parse("").is_err());