Rust Type Code

// 使用std::any::type_name可以打印数据类型

fn print_type_of<T>(_: &T) {
    println!("type is = {}", std::any::type_name::<T>())
}

• impl copy

❯ cargo run
    Finished dev [unoptimized + debuginfo] target(s) in 0.42s
     Running `target/debug/guessing_game`
type is = alloc::string::String
str2 is: "tosei"
type is = alloc::string::String
str is: "tosei"
type is = &[u8]
str1_bytes is: [116, 111, 115, 101, 105]
type is = [u8; 5]
str1_num is: [116, 111, 115, 101, 105]
type is = alloc::vec::Vec<u8>
vec_from_slice is [116, 111, 115, 101, 105]
type is = alloc::vec::Vec<u8>
str1_vec is [116, 111, 115, 101, 105]
type is = alloc::string::String
str_from_vec is "tosei"
type is = alloc::vec::Vec<u8>
vec_from_string is [116, 111, 115, 101, 105]
type is = u32
bytes_u32 is 203435063

• struct

use std::rc::Rc;
#[derive(Debug)]
struct Transfer {
trans: Rc<Vec<u8>>,
message: String,
}
impl Transfer {
fn new(trans: &[u8], message: &str) -> Self {
Transfer {
trans: Rc::new(trans.to_owned()),
message: message.to_owned(),
}
}
fn trans(&amp;self) -&gt; Vec&lt;u8&gt; {
    self.trans.clone().to_vec()
}

fn message(&amp;self) -&gt; String {
    self.message.clone()
}

}
fn main() {
let transfer = Transfer::new(b"tosei", "hello");
let trans = transfer.trans();
let message = transfer.message();
// Vec -> [u8]
let trans_array: [u8; 5] = trans.try_into().unwrap();
println!("trans_array is: {:?}", trans_array);
// String  -&gt; [u8]
let message_array: [u8; 5] = message.as_bytes().try_into().unwrap();
println!("message_array is: {:?}", message_array);

// [u8] -&gt; &amp;str
let trans_str = std::str::from_utf8(&amp;trans_array).unwrap();
println!("trans_str is: {:?}", trans_str);

}

❯ cargo run
   Compiling guessing_game v0.1.0 (/Users/tosei/workspace/practice/rust/rust-p/rust_small_demo)
    Finished dev [unoptimized + debuginfo] target(s) in 0.82s
     Running `target/debug/guessing_game`
trans_array is: [116, 111, 115, 101, 105]
message_array is: [104, 101, 108, 108, 111]
trans_str is: "tosei"