Struct Origin 

pub struct Origin {
    pub reason: Reason,
    pub span: NodeSpan,
    /* private fields */
}

Where a constraint came from, and — once inference has moved types around — where each of its two types came from.

Fields

reason: Reason

Why the two types were required to match.

span: NodeSpan

The source text this constraint is about. A failure here draws its caret at this span.

Implementations

impl Origin

pub fn explanation(&self) -> Option<Cause>

Where the type this constraint clashed on came from, when the constraint is not itself where it came from.

This is what a diagnostic’s secondary label and its rule note are both read off. The left side is preferred because that is the declared or expected side by convention (see Constraint), so “expected because of …” reads about the right one; the right side answers when only it was rewritten.

Trait Implementations

impl Clone for Origin

fn clone(&self) -> Origin

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Origin

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

Formats the value using the given formatter.

impl PartialEq for Origin

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Origin