Error code E0748

A raw string isn't correctly terminated because the trailing # count doesn't match its leading # count.

Erroneous code example:

#![allow(unused)]
fn main() {
let dolphins = r##"Dolphins!"#; // error!
}

To terminate a raw string, you have to have the same number of # at the end as at the beginning. Example:

#![allow(unused)]
fn main() {
let dolphins = r#"Dolphins!"#; // One `#` at the beginning, one at the end so
                               // all good!
}