Error code E0424

The self keyword was used inside of an associated function without a “self receiver” parameter.

Erroneous code example:

struct Foo;

impl Foo {
    // `bar` is a method, because it has a receiver parameter.
    fn bar(&self) {}

    // `foo` is not a method, because it has no receiver parameter.
    fn foo() {
        self.bar(); // error: `self` value is a keyword only available in
                    //        methods with a `self` parameter
    }
}

The self keyword can only be used inside methods, which are associated functions (functions defined inside of a trait or impl block) that have a self receiver as its first parameter, like self, &self, &mut self or self: &mut Pin<Self> (this last one is an example of an “arbitrary self type”).

Check if the associated function’s parameter list should have contained a self receiver for it to be a method, and add it if so. Example:

struct Foo;

impl Foo {
    fn bar(&self) {}

    fn foo(self) { // `foo` is now a method.
        self.bar(); // ok!
    }
}

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