References
Something like &String, the concept is similar to a Pointer in C/C++/Golang/…
It will not take the ownership, thus we can drop some tuple code to make it simpler.
Borrowing
having references as function parameters
Scope
A reference’s scope starts from where it is introduced and continues through the last time that reference is used.
let mut s = String::from("hello");
let r1 = &s; // no problem
let r2 = &s; // no problem
println!("{} and {}", r1, r2);
// r1 and r2 are no longer used after this point
let r3 = &mut s; // no problem
println!("{}", r3);
Recapitulation
- At any given time, you can have either one mutable or any number of immutable references.
- References must always be valid. (Dangling references will not be allowed in Rust by compiler)
