Enum rustc_trait_selection::infer::region_constraints::Constraint

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

Represents a constraint that influences the inference process.

Variants

VarSubVar(RegionVid, RegionVid)

A region variable is a subregion of another.

RegSubVar(Region<'tcx>, RegionVid)

A concrete region is a subregion of region variable.

VarSubReg(RegionVid, Region<'tcx>)

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<'tcx>, Region<'tcx>)

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

Implementations

impl Constraint<'_>

pub fn involves_placeholders(&self) -> bool

Trait Implementations

impl<'tcx> Clone for Constraint<'tcx>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'tcx> Debug for Constraint<'tcx>

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

Formats the value using the given formatter.

impl<'tcx> Hash for Constraint<'tcx>

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

where __H: Hasher,

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<'tcx> PartialEq for Constraint<'tcx>

fn eq(&self, other: &Constraint<'tcx>) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

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

impl<'tcx> Copy for Constraint<'tcx>

impl<'tcx> Eq for Constraint<'tcx>

impl<'tcx> StructuralPartialEq for Constraint<'tcx>

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 24 bytes

Size for each variant:

• VarSubVar: 8 bytes
• RegSubVar: 12 bytes
• VarSubReg: 12 bytes
• RegSubReg: 20 bytes