Struct rustc_trait_selection::infer::outlives::env::OutlivesEnvironment

pub struct OutlivesEnvironment<'tcx> {
    pub param_env: ParamEnv<'tcx>,
    free_region_map: FreeRegionMap<'tcx>,
    region_bound_pairs: IndexSet<OutlivesPredicate<GenericKind<'tcx>, Region<'tcx>>, BuildHasherDefault<FxHasher>>,
}

The OutlivesEnvironment collects information about what outlives what in a given type-checking setting. For example, if we have a where-clause like where T: 'a in scope, then the OutlivesEnvironment would record that (in its region_bound_pairs field). Similarly, it contains methods for processing and adding implied bounds into the outlives environment.

Other code at present does not typically take a &OutlivesEnvironment, but rather takes some of its fields (e.g., process_registered_region_obligations wants the region-bound-pairs). There is no mistaking it: the current setup of tracking region information is quite scattered! The OutlivesEnvironment, for example, needs to sometimes be combined with the middle::RegionRelations, to yield a full picture of how (lexical) lifetimes interact. However, I’m reluctant to do more refactoring here, since the setup with NLL is quite different. For example, NLL has no need of RegionRelations, and is solely interested in the OutlivesEnvironment. -nmatsakis

Fields

param_env: ParamEnv<'tcx>

free_region_map: FreeRegionMap<'tcx>

region_bound_pairs: IndexSet<OutlivesPredicate<GenericKind<'tcx>, Region<'tcx>>, BuildHasherDefault<FxHasher>>

Implementations

impl<'tcx> OutlivesEnvironment<'tcx>

pub fn new(param_env: ParamEnv<'tcx>) -> OutlivesEnvironment<'tcx>

Create a new OutlivesEnvironment without extra outlives bounds.

pub fn with_bounds( param_env: ParamEnv<'tcx>, extra_bounds: impl IntoIterator<Item = OutlivesBound<'tcx>> ) -> OutlivesEnvironment<'tcx>

Create a new OutlivesEnvironment with extra outlives bounds.

pub fn free_region_map(&self) -> &FreeRegionMap<'tcx>

Borrows current value of the free_region_map.

pub fn region_bound_pairs( &self ) -> &IndexSet<OutlivesPredicate<GenericKind<'tcx>, Region<'tcx>>, BuildHasherDefault<FxHasher>>

Borrows current region_bound_pairs.

Trait Implementations

impl<'tcx> Clone for OutlivesEnvironment<'tcx>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

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: 192 bytes