How to convert char to string?

问题

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

---

I tried to print one symbol by io::println function

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

But I got next error:

$ 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

How to convert char to string?

UPDATE

Direct typecast does not work:

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

It returns:

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

回答1:

Use char::to_string, which is from the ToString trait:

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

回答2:

You can now use c.to_string(), where c is your variable of type char.

来源：https://stackoverflow.com/questions/16267578/how-to-convert-char-to-string