Rust core::result::Result.and用法及代码示例

let x:Result<u32, &str> = Ok(2);
let y:Result<&str, &str> = Err("late error");
assert_eq!(x.and(y), Err("late error"));

let x:Result<u32, &str> = Err("early error");
let y:Result<&str, &str> = Ok("foo");
assert_eq!(x.and(y), Err("early error"));

let x:Result<u32, &str> = Err("not a 2");
let y:Result<&str, &str> = Err("late error");
assert_eq!(x.and(y), Err("not a 2"));

let x:Result<u32, &str> = Ok(2);
let y:Result<&str, &str> = Ok("different result type");
assert_eq!(x.and(y), Ok("different result type"));