Enum Mismatch 

pub enum Mismatch {
    Different(Box<(Ty, Ty)>),
    Arity(usize, usize),
    Infinite,
    Effects(String),
    UnknownEffects,
}

Variants

Different(Box<(Ty, Ty)>)

Boxed because a Ty is a tree and this is the error path: making every successful unification carry the size of a failed one is the wrong trade.

Arity(usize, usize)

Infinite

Effects(String)

Two function types agree on their arguments and result but not on what they do.

UnknownEffects

The same, where what the actual side may do is not yet known — an unsolved row variable against a context whose row is closed. Distinct from Mismatch::Effects because there is no effect to name, and a message that names none is one no user can act on.

Trait Implementations

impl Clone for Mismatch

fn clone(&self) -> Mismatch

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Mismatch

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

Formats the value using the given formatter.