Mastering Rust - Second Edition

Generic implementations

We can also write impl blocks for our generic types too, but it gets verbose here because of the extra generic type parameters, as we'll see. Let's implement a new() method on our Container<T> struct:

// generic_struct_impl.rsstruct Container<T> {    item: T}impl Container<T> {    fn new(item: T) -> Self {        Container { item }    }}fn main() {    // stuff}

Let's compile this:

The error message cannot find our generic type T. When writing an impl block for any generic type, we need to declare the generic type parameter before using it within our type. T is just like a variable—a type variable—and we need to declare it. Therefore, ...