rust_logo.jpg
类型转换在许多语言中都有，在 Rust 中类型转换很简单使用 as 后面跟着要转换为的类型。
fn main(){
let f = 24.4321_f32;
let i = f as u8;
let c = i as char;
println!("{} {} {} ", f, i, c);
println!("{} {} ", 12 as char, 14 as char);
}
fn main(){
let f = File::open("test.txt");
let _f = match f {
Ok(file) => file,
Err(error) => {
panic!("There was a problem opening the file: {:?}",error);
},
};
}
