Enum Outcome 

pub enum Outcome {
    Changed,
    Unchanged,
}

Whether a pass changed the unit on a given run.

A pass returns Outcome::Changed when it modified the unit and Outcome::Unchanged when it left it untouched. The PassManager uses this signal to decide whether a fixpoint loop has settled (a full sweep with no Changed is a fixpoint) and to build the Report. Reporting Unchanged after mutating the unit breaks fixpoint termination, so the value is taken at its word — keep it honest.

Variants

Changed

The pass modified the unit.

Unchanged

The pass left the unit unchanged.

Implementations

impl Outcome

pub fn changed(self) -> bool

True if this is Outcome::Changed.

Examples

use pass_lang::Outcome;

assert!(Outcome::Changed.changed());
assert!(!Outcome::Unchanged.changed());

pub fn from_changed(changed: bool) -> Self

Build an outcome from a “did it change?” flag.

The common shape of a Pass::run body: compute the transform, then report whether it actually altered the unit.

Examples

use pass_lang::Outcome;

assert_eq!(Outcome::from_changed(true), Outcome::Changed);
assert_eq!(Outcome::from_changed(false), Outcome::Unchanged);

Trait Implementations

impl Clone for Outcome

fn clone(&self) -> Outcome

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Outcome

impl Debug for Outcome

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

Formats the value using the given formatter.

impl Eq for Outcome

impl Hash for Outcome

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Outcome

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for Outcome

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Outcome