&str은 문자열 슬라이스입니다. 문자열 슬라이스는 UTF-8로 인코딩된 문자열 데이터를 의미합니다. 문자열 리터럴("Hello")은 프로그램 바이너리에 저장됩니다.

러스트의 String타입은 실제로는 문자열을 이루는 바이트에 대한 백터(Vec<u8>)입니다. Vec<T>가 T를 소유하고 있듯이, String이 가리키고 있는 문자열은 String의 소유입니다.

As with many other types String::from() creates a string from a string literal; String::new() creates a new empty string, to which string data can be added using the push() and push_str() methods.

The format!() macro is a convenient way to generate an owned string from dynamic values. It accepts the same format specification as println!().

You can borrow &str slices from String via & and optionally range selection. If you select a byte range that is not aligned to character boundaries, the expression will panic. The chars iterator iterates over characters and is preferred over trying to get character boundaries right.

For C++ programmers: think of &str as std::string_view from C++, but the one that always points to a valid string in memory. Rust String is a rough equivalent of std::string from C++ (main difference: it can only contain UTF-8 encoded bytes and will never use a small-string optimization).

Byte strings literals allow you to create a &[u8] value directly:

fn main() {
    println!("{:?}", b"abc");
    println!("{:?}", &[97, 98, 99]);
}