铁 rust 中的泛型：不能将`<；T作为添加>；：：Output`除以`{Float}`

我正在学习Rust中的泛型.我创建了一个带有计算其面积的函数的Alzium struct 的简单用例.请考虑下面的例子:

#[derive(Debug)]
struct Trapezium<T> {
    a: T,
    b: T,
    h: T,
    area: T,
    perimeter: T,
}

fn calc_area<T: std::ops::Add>(a: T, b: T, h: T) -> T {

    return (a+b)/2.0/h;
}

fn main() {

    let mut t = Trapezium {a: 3.1, b: 6.9, h: 2.5, area: 0.0, perimeter: 0.0};
    t.area    = calc_area(t.a, t.b, t.h);
    println!("t: {:?}", t);
}

我在calc_area的函数中遇到了问题，因为除以float64.请在下面找到我的编译错误:

Compiling geometric v0.1.0 (/Users/mabalenk/repo/git/rustup/src/geometric)
error[E0369]: cannot divide `<T as Add>::Output` by `{float}`
  --> src/main.rs:12:17
   |
12 |     return (a+b)/2.0/h;
   |            -----^--- {float}
   |            |
   |            <T as Add>::Output
   |
help: consider further restricting the associated type
   |
10 | fn calc_area<T: std::ops::Add>(a: T, b: T, h: T) -> T where <T as Add>::Output: Div<f64> {
   |                                                       ++++++++++++++++++++++++++++++++++

For more information about this error, try `rustc --explain E0369`.
error: could not compile `geometric` (bin "geometric") due to previous error

我对增加where <T as Add>::Output: Div<f64>条款的建议感到担忧.Div<f64>不再使其成为通用产品.另外，添加此子句无助于编译代码.而且，它确实使源代码变得非常混乱.

你能推荐一个优雅的"教科书"解决方案，让我的基本例子发挥作用吗？