sciolizer

  pub trait ToOwned {
    type Owned: Borrow<Self>;
    fn clone_into(&self, target: &mut Self::Owned) { ... }
  }

  pub trait StreamExt: Stream {
    type Item;
    fn map<T, F>(self, f: F) -> Map<Self, F>
       where F: FnMut(Self::Item) -> T,
             Self: Sized { ... }
  }

  pub trait Mul<Rhs> {
      type Output;
  
      fn mul(self, rhs: Rhs) -> Self::Output;
  }

  impl Mul<f32> for i32 {
    type Output = f32;
  
    fn mul(self, rhs: f32) -> Self::Output {
      self as f32 * rhs
    }
  }

  Mul[(i32,f32)] = (Output=f32, mul={self as f32 * rhs})