trait FromResidual::Residual> { fn from_residual(residual: R) -> Self; } trait Try { type Residual; } fn w<'a, T: 'a, F: Fn(&'a T)>() { let b: &dyn FromResidual = &(); //~^ ERROR: the trait `FromResidual` cannot be made into an object //~| ERROR: the trait `FromResidual` cannot be made into an object } fn main() {}