Rust核心机制(二)\#
Understanding Ownership\#
所有权(Ownership)是Rust最独特的功能，它对语言的其他部分有着非常重大的影响，使Rust在没有垃圾回收机制的情况下保证了内存的安全
What Is Ownership?\#
fn main() {
let s = String::from("Hello");
takes_ownership(s);
let x = 5;
makes_copy(x);
}
fn takes_ownership(some_string: String) {
println!("{}", some_string);
}
fn makes_copy(some_integer: i32) {
println!("{}", some_integer);
}
References and Borrowing\#
fn main() {
let s1 = String::from("hello");
let len = calculate_length(&s1);
println!("The length of '{}' is {}.", s1, len);
}
fn calculate_length(s: &String) -> usize {
s.len()
}
fn main() {
let mut s = String::from("hello");
let r1 = &s;
let r2 = &s;
println!("{} and {}", r1, r2);
let r3 = &mut s;
println!("{}", r3);
}
fn main() {
let reference_to_nothing = dangle();
}
fn dangle() -> &String {
let s = String::from("hello");
&s
}