Error code E0753

An inner doc comment was used in an invalid context.

Erroneous code example:

fn foo() {} //! foo // ^ error! fn main() {}

Inner document can only be used before items. For example:

//! A working comment applied to the module! fn foo() { //! Another working comment! } fn main() {}

In case you want to document the item following the doc comment, you might want to use outer doc comment:

#![allow(unused)] fn main() { /// I am an outer doc comment #[doc = "I am also an outer doc comment!"] fn foo() { // ... } }