Enum Constraint

pub enum Constraint<'db> {
    VarSubVar(RegionVid, RegionVid),
    RegSubVar(Region<'db>, RegionVid),
    VarSubReg(RegionVid, Region<'db>),
    RegSubReg(Region<'db>, Region<'db>),
}

Represents a constraint that influences the inference process.

Variants

VarSubVar(RegionVid, RegionVid)

A region variable is a subregion of another.

RegSubVar(Region<'db>, RegionVid)

A concrete region is a subregion of region variable.

VarSubReg(RegionVid, Region<'db>)

A region variable is a subregion of a concrete region. This does not directly affect inference, but instead is checked after inference is complete.

RegSubReg(Region<'db>, Region<'db>)

A constraint where neither side is a variable. This does not directly affect inference, but instead is checked after inference is complete.

Implementations

impl<'db> Constraint<'db>

pub fn involves_placeholders(&self) -> bool

Trait Implementations

impl<'db> Clone for Constraint<'db>

fn clone(&self) -> Constraint<'db>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'db> Debug for Constraint<'db>

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

Formats the value using the given formatter.

impl<'db> Hash for Constraint<'db>

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<'db> PartialEq for Constraint<'db>

fn eq(&self, other: &Constraint<'db>) -> 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<'db> Eq for Constraint<'db>

impl<'db> StructuralPartialEq for Constraint<'db>