Type Definition rustc_middle::traits::SelectionResult

pub type SelectionResult<'tcx, T> = Result<Option<T>, SelectionError<'tcx>>;

When performing resolution, it is typically the case that there can be one of three outcomes:

• Ok(Some(r)): success occurred with result r
• Ok(None): could not definitely determine anything, usually due to inconclusive type inference.
• Err(e): error e occurred

Layout

Note: Unable to compute type layout, possibly due to this type having generic parameters. Layout can only be computed for concrete, fully-instantiated types.