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# Error code E0405

The code refers to a trait that is not in scope.

Erroneous code example:

    #![allow(unused)]
    fn main() {
    struct Foo;

    impl SomeTrait for Foo {} // error: trait `SomeTrait` is not in scope
    }

Please verify that the name of the trait wasn’t misspelled and ensure that it was imported. Example:

    #![allow(unused)]
    fn main() {
    #[cfg(for_demonstration_only)]
    // solution 1:
    use some_file::SomeTrait;

    // solution 2:
    trait SomeTrait {
        // some functions
    }

    struct Foo;

    impl SomeTrait for Foo { // ok!
        // implements functions
    }
    }