怎么能學(xué)會(huì)Rust

many people report a sense of high "cognitive overhead" in using it, and "learning curve" remains the most common reason not to use Rust. The fact is that, even after you learn how the Rust borrow checker works, there remain a lot of "small details" that you have to get just right to get your Rust program to compile.

翻譯過來就是：這玩意兒會(huì)有很高的認(rèn)知開銷，陡峭的 學(xué)習(xí)曲線 是大家不會(huì)（沒法）使用Rust的最常見原因。

因?yàn)榧词沽私饬薘ust里面最麻煩最焦頭爛額的特性：借用檢查器（所有權(quán)機(jī)制）的工作原理后，仍有許多亂七八糟的小細(xì)節(jié)需要去正確處理，否則Rust編譯器會(huì)好好的教你做人……

戰(zhàn)略上要藐視敵人

• 引用與解引用的hello world的例子：

let reference = &4;
match reference {
    &val => println!("Got a value via destructuring: {:?}", val),
}
match *reference {
    val => println!("Got a value via dereferencing: {:?}", val),
}

let value = 5;
let mut mut_value = 6;
match value {
    ref r => println!("Got a reference to a value: {:?}", r),
}
match mut_value {
    ref mut m => {
        *m += 10;
        println!("We added 10. `mut_value`: {:?}", m);
    },
}

• 泛型的hello world：

impl <A: TraitB + TraitC, D: TraitE + TraitF> MyTrait<A, D>
for YourType {}

impl <A, D> MyTrait<A, D> for YourType where
    A: TraitB + TraitC,
    D: TraitE + TraitF {}

• 生命周期的hello world

#[derive(Debug)]
 struct Borrowed<'a> {
     x: &'a i32,
 }
impl<'a> Default for Borrowed<'a> {
    fn default() -> Self {
        Self {
            x: &10,
        }
    }
}

//帶弧線的幾何面積計(jì)算
double OGRCircularString::get_AreaOfCurveSegments() const
{
    double dfArea = 0.0;
    for (int i = 0; i < getNumPoints() - 2; i += 2)
    {
        const double x0 = getX(i);
        const double y0 = getY(i);
        const double x1 = getX(i + 1);
        const double y1 = getY(i + 1);
        const double x2 = getX(i + 2);
        const double y2 = getY(i + 2);
        double R = 0.0;
        double cx = 0.0;
        double cy = 0.0;
        double alpha0 = 0.0;
        double alpha1 = 0.0;
        double alpha2 = 0.0;
        if (OGRGeometryFactory::GetCurveParameters(
                x0, y0, x1, y1, x2, y2, R, cx, cy, alpha0, alpha1, alpha2))
        {
            const double delta_alpha01 = alpha1 - alpha0;
            const double delta_alpha12 = alpha2 - alpha1; 
            dfArea += 0.5 * R * R *
                      fabs(delta_alpha01 - sin(delta_alpha01) + delta_alpha12 -
                           sin(delta_alpha12));
        }
    }
    return dfArea;
}

用Rust封裝之后，就是這個(gè)：