Enum Followed 

pub enum Followed {
    Type(Type),
    Exhausted,
    NotAnAlias,
}

What following an imported name across the file boundary, as a type alias, found.

A plain Option<Type> cannot tell two failure shapes apart, and named_type’s fallback has to answer them differently: “this name is not an alias at all” keeps its own nominal identity, exactly as it always has, while “this name is an alias, but the chain following it was cut by MAX_DEPTH” must answer nothing — see addendum B of task 4.16. The distinction has to survive an arbitrary number of cross-file hops, because the bound can be spent several files away from the frame that first asked; every hop threads this enum rather than collapsing it back to Option until the walk has fully unwound.

Variants

Type(Type)

The type the alias names.

Exhausted

The name is an alias, but MAX_DEPTH cut the chain before it resolved to a type.

NotAnAlias

The name does not name a type alias at all.

Trait Implementations

impl Clone for Followed

fn clone(&self) -> Followed

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Followed

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for Followed

impl PartialEq for Followed

fn eq(&self, other: &Followed) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Followed