Error code E0758

A multi-line (doc-)comment is unterminated.

Erroneous code example:

#![allow(unused)]
fn main() {
/* I am not terminated!
}

The same goes for doc comments:

#![allow(unused)]
fn main() {
/*! I am not terminated!
}

You need to end your multi-line comment with */ in order to fix this error:

#![allow(unused)]
fn main() {
/* I am terminated! */
/*! I am also terminated! */
}