# Error code E0705

A `#![feature]` attribute was declared for a feature that is stable in the current edition, but not in all editions.

Erroneous code example:

    #![allow(unused)]
    #![feature(rust_2018_preview)]
    #![feature(test_2018_feature)] // error: the feature
    fn main() {
                                   // `test_2018_feature` is
                                   // included in the Rust 2018 edition
    }