title: How can I refer to a trait's generic parameter in rust?
body: <p>for a trait with a type parameter I can reference it in the implementation like so:</p>
  <pre class="lang-rust prettyprint-override"><code>impl Mul for Foo {
      type Output = Bar;
      fn mul(self, rhs: self) -&gt; Self::Output {
          unimplemented!()
      }
  }
  </code></pre>
  <p>(<code>Self::Output</code> is what I'm referring to, or <code>&lt;Self as Mul&gt;::Output</code>)</p>
  <p>is it possible to do the same for a trait's generic parameters? for example:</p>
  <pre class="lang-rust prettyprint-override"><code>impl Into&lt;Bar&gt; for Foo {
      fn into(foo: Self) -&gt; &lt;Self as Into&gt;::??? {
          unimplemented!()
      }
  
  }
  </code></pre>
  <p>I'm at a loss for what to replace the question marks with.</p>