Matching a generic parameter to an associated type in an impl

Question

I have a trait with an associated type and a generic struct::

trait Generator {
    type Foo;
    fn generate(&self) -> Self::Foo;
}

struct Baz

        

Answer 1

The trick is to only have a single generic parameter:

trait Generator {
    type Foo;
    fn generate(&self) -> Self::Foo;
}

struct Baz
where
    G: Generator,
{
    generator: G,
    vec: Vec,
}

impl Baz
where
    G: Generator,
{
    fn add_foo(&mut self) {
        self.vec.push(self.generator.generate());
    }
}

Since the vector will contain G::Foo, we can actually just say that.

The Rust style is snake_case, so I updated that as well as made the type parameter G to help the reader.