# Error code E0366

An attempt was made to implement `Drop` on a concrete specialization of a generic type. An example is shown below:

    #![allow(unused)]
    fn main() {
    struct Foo<T> {
        t: T
    }

    impl Drop for Foo<u32> {
        fn drop(&mut self) {}
    }
    }

This code is not legal: it is not possible to specialize `Drop` to a subset of implementations of a generic type. One workaround for this is to wrap the generic type, as shown below:

    #![allow(unused)]
    fn main() {
    struct Foo<T> {
        t: T
    }

    struct Bar {
        t: Foo<u32>
    }

    impl Drop for Bar {
        fn drop(&mut self) {}
    }
    }