摘要：
In Rust, the exclamation mark (!) after a name indicates that it is a macro rather than a function. Macros and functions in Rust are called differentl 阅读全文
摘要：
We can use Reusltenum to do error handling type Result<V, E> { Err(E), Ok(V) } Example: // (): empty // uszie: just return a integre as error for demo 阅读全文