slicestring is a crate for slicing Strings. It provides the slice() method for String and &str. It takes a std::ops::Range as an argument. It slices the String or &str and returns the sliced one as a String.

use slicestring::Slice;
let mut s = "hello world!";
s = s.slice(..5);
assert_eq!("hello", s);

It also works with emoticons since the slice method takes into account characters.

use slicestring::Slice;
let mut s = String::from("hello 😃");
s = s.slice(5..);
assert_eq!("😃", s);