如何将char转换为字符串？

Question

This Question pertains to a pre-release version of Rust.
This younger Question is similar.

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我试图通过io::println功能

fn main() { 
    io::println('c'); 
} 

打印一个符号，但我得到了一个错误：

$ rustc pdst.rs 
pdst.rs:2:16: 2:19 error: mismatched types: expected `&str` but found `char` (expected &str but found char) 
pdst.rs:2  io::println('c'); 
          ^~~ 
error: aborting due to previous error 

如何字符转换为字符串？

UPDATE

直接类型转换不起作用：

let text:str = 'c'; 
let text:&str = 'c'; 
let text:@str = 'c'; 
let text:~str = 'c'; 

它返回：

pdst.rs:7:13: 7:16 error: bare `str` is not a type 
pdst.rs:7  let text:str = 'c'; 
         ^~~ 
pdst.rs:7:19: 7:22 error: mismatched types: expected `~str` but found `char` (expected ~str but found char) 
pdst.rs:7  let text:str = 'c'; 
          ^~~ 
pdst.rs:8:20: 8:23 error: mismatched types: expected `&str` but found `char` (expected &str but found char) 
pdst.rs:8  let text:&str = 'c'; 
           ^~~ 
pdst.rs:9:20: 9:23 error: mismatched types: expected `@str` but found `char` (expected @str but found char) 
pdst.rs:9  let text:@str = 'c'; 
           ^~~ 
pdst.rs:10:20: 10:23 error: mismatched types: expected `~str` but found `char` (expected ~str but found char) 
pdst.rs:10  let text:~str = 'c'; 
           ^~~ 
error: aborting due to 5 previous errors 

Answer 1

使用char::to_string，这是strangely undocumented：

fn main() { 
    io::println('c'.to_string()); 
} 

Answer 2

您现在可以使用c.to_string()，其中c是您的变量类型char。