How to Convert a String into a &'static Str in Rust

Created Apr 29, 2022 at 10:33

Modified Apr 29, 2022 at 12:22

Using slicing Syntax

To go from a String to a slice &'a str you can use slicing syntax. See the following example:

// Rust 1.0+

fn main() {
  let s: String = "abc".to_owned();

  // take a full slice of the string
  let slice: &str = &s[..];

  println!("{}", slice);
}

abc

Using & Operator

You can use the fact that String implements Deref<Target=str> and perform an explicit reborrowing:

fn main() {
  let s: String = "abc".to_owned();

  // *s : str (via Deref<Target=str>)
  // &*s: &str
  let slice: &str = &*s;
  println!("{}", slice);
}

abc

Using unsafe Code

As of Rust version 1.26, it is possible to convert a String to &'static str without using unsafe code:

// Rust 1.26+

fn string_to_str(s: String) -> &'static str {
  Box::leak(s.into_boxed_str())
}

fn main() {
  let s: String = "abc".to_owned();

  let slice: &str = string_to_str(s);
  println!("{}", slice);
}