我试图访问枚举内装箱结构的属性，但我不知道如何与std::boxed::Box进行模式匹配

enum ArithExp {
    Sum {
        lhs: Box<ArithExp>,
        rhs: Box<ArithExp>,
    },
    Mul {
        lhs: Box<ArithExp>,
        rhs: Box<ArithExp>,
    },
    Num {
        value: f64,
    },
}

fn num(value: f64) -> std::boxed::Box<ArithExp> {
    Box::new(ArithExp::Num { value })
}

let mut number = num(1.0);
match number {
    ArithExp::Num { value } => println!("VALUE = {}", value),
}

字符串
我得到以下错误：

error[E0308]: mismatched types
  --> src/main.rs:22:9
   |
22 |         ArithExp::Num { value } => println!("VALUE = {}", value),
   |         ^^^^^^^^^^^^^^^^^^^^^^^ expected struct `std::boxed::Box`, found enum `main::ArithExp`
   |
   = note: expected type `std::boxed::Box<main::ArithExp>`
              found type `main::ArithExp`

型
访问属性的正确方法是什么？