如何将char转换为字符串？

Question

此问题适用于Rust的预发布版本.
这个年轻的问题很相似.

---

我试图按io::println功能打印一个符号

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

但我得到了下一个错误:

$ 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

如何将char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,这是奇怪的未记录:

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

Answer 2

您现在可以使用c.to_string(),c您的类型变量在哪里char.

Answer 3

使用.to_string()将String在堆上分配。通常这不是任何问题，但如果您想避免这种情况并想&str直接获取切片，您也可以使用

let mut tmp = [0u8; 4];
let your_string = c.encode_utf8(&mut tmp));