Struct rustc_middle::ty::inhabitedness::DefIdForest

pub struct DefIdForest {
    root_ids: SmallVec<[DefId; 1]>,
}

Represents a forest of DefIds closed under the ancestor relation. That is, if a DefId representing a module is contained in the forest then all DefIds defined in that module or submodules are also implicitly contained in the forest.

This is used to represent a set of modules in which a type is visibly uninhabited.

Fields

root_ids: SmallVec<[DefId; 1]>

The minimal set of DefIds required to represent the whole set. If A and B are DefIds in the DefIdForest, and A is a descendant of B, then only B will be in root_ids. We use a SmallVec here because (for its use for caching inhabitedness) its rare that this will contain even two IDs.

Implementations

impl<'tcx> DefIdForest

pub fn empty() -> DefIdForest

Creates an empty forest.

pub fn full(tcx: TyCtxt<'tcx>) -> DefIdForest

Creates a forest consisting of a single tree representing the entire crate.

pub fn from_id(id: DefId) -> DefIdForest

Creates a forest containing a DefId and all its descendants.

pub fn is_empty(&self) -> bool

Tests whether the forest is empty.

pub fn contains(&self, tcx: TyCtxt<'tcx>, id: DefId) -> bool

Tests whether the forest contains a given DefId.

pub fn intersection<I>(tcx: TyCtxt<'tcx>, iter: I) -> DefIdForest where
    I: IntoIterator<Item = DefIdForest>, 

Calculate the intersection of a collection of forests.

pub fn union<I>(tcx: TyCtxt<'tcx>, iter: I) -> DefIdForest where
    I: IntoIterator<Item = DefIdForest>, 

Calculate the union of a collection of forests.

Trait Implementations

impl Clone for DefIdForest

pub fn clone(&self) -> DefIdForest

Returns a copy of the value.

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

Performs copy-assignment from source.