tvl-depot/users/Profpatsch/blog/notes/rust-string-conversions.md
Profpatsch 70d01b201f docs(users/profpatsch/blog): rust string conversions: &str -> &OsStr
Change-Id: I215cd311551d54ce42c71d4e80ea18f9a17d4cf8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3879
Tested-by: BuildkiteCI
Reviewed-by: Profpatsch <mail@profpatsch.de>
2021-11-15 00:31:11 +00:00

53 lines
2.1 KiB
Markdown

# Converting between different String types in Rust
```
let s: String = ...
let st: &str = ...
let u: &[u8] = ...
let b: [u8; 3] = b"foo"
let v: Vec<u8> = ...
let os: OsString = ...
let ost: OsStr = ...
From To Use Comment
---- -- --- -------
&str -> String String::from(st)
&str -> &[u8] st.as_bytes()
&str -> Vec<u8> st.as_bytes().to_owned() via &[u8]
&str -> &OsStr OsStr::new(st)
String -> &str &s alt. s.as_str()
String -> &[u8] s.as_bytes()
String -> Vec<u8> s.into_bytes()
String -> OsString OsString::from(s)
&[u8] -> &str str::from_utf8(u).unwrap()
&[u8] -> String String::from_utf8(u).unwrap()
&[u8] -> Vec<u8> u.to_owned()
&[u8] -> &OsStr OsStr::from_bytes(u) use std::os::unix::ffi::OsStrExt;
[u8; 3] -> &[u8] &b[..] byte literal
[u8; 3] -> &[u8] "foo".as_bytes() alternative via utf8 literal
Vec<u8> -> &str str::from_utf8(&v).unwrap() via &[u8]
Vec<u8> -> String String::from_utf8(v)
Vec<u8> -> &[u8] &v
Vec<u8> -> OsString OsString::from_vec(v) use std::os::unix::ffi::OsStringExt;
&OsStr -> &str ost.to_str().unwrap()
&OsStr -> String ost.to_os_string().into_string() via OsString
.unwrap()
&OsStr -> Cow<str> ost.to_string_lossy() Unicode replacement characters
&OsStr -> OsString ost.to_os_string()
&OsStr -> &[u8] ost.as_bytes() use std::os::unix::ffi::OsStringExt;
OsString -> String os.into_string().unwrap() returns original OsString on failure
OsString -> &str os.to_str().unwrap()
OsString -> &OsStr os.as_os_str()
OsString -> Vec<u8> os.into_vec() use std::os::unix::ffi::OsStringExt;
```
## Source
Original source is [this document on Pastebin](https://web.archive.org/web/20190710121935/https://pastebin.com/Mhfc6b9i)