准备搞起一个《Rust那些事》，一起来学习呀~
Rust引用
1.引用
Rust中，使用&T表示类型T的引用类型，跟C 的引用比较来说不太一样，简单理解：等同于const T*，
Rust版：
代码语言：javascript复制pub fn get_rf() {
let mut a : i32 = 1;
let mut b : i32 = 2;
let c : i32 = 3;
let d : &mut i32 = &mut a; // d points to a now
*d = 2; //OK, change a
// d = &mut b; // ILLEGAL, d is not mutable
let mut e : &mut i32;
// e = &a; // illegal d already has a mutable reference to a
e = &mut b;
// e = &mut c; // Illegal, c is not mutable
}
C 版：
代码语言：javascript复制void get_rf() {
int a = 1, b = 2;
const int c = 3;
int* const d = &a; // d can't change, but it points to something that can
*d = 2; // OK
//d = &b; // ILLEGAL
int* e; // e can change, as can the thing it points to
// e = &a, legal in c since there's no borrow checker
e = &b; // OK, e points to b;
e = &c; // ILLEGAL, c is const
}
例子中**&mut称为可变引用**，由于&创建出来的引用是只读，所以这里可以用&mut。
2.解引用
Rust自动解引用：
- Rust版：
let a = vec![1,2,3];
let b = &a;
let c = &b;
let one = rrv[0];
- C 版：
const vector<int> a{1, 2, 3};
const vector<int>* const b = &a;
const vector<int> *const * const c = &b;
int one = (**c)[0];
可以看到C 需要手动解。
像遇到.调用一般自动解引用，诸如：
r.first_name
numbers.sort();
手动解引用：
如果你要给一个引用赋值，必须手动解。
代码语言：javascript复制let mut a = 5;
let rra = &mut &mut a;
// rra = 6; // ILLEGAL, must derefence manually
**rra = 6;
