Trait rustc_infer::infer::nll_relate::TypeRelatingDelegate[−][src]

pub trait TypeRelatingDelegate<'tcx> {
    fn param_env(&self) -> ParamEnv<'tcx>;

    fn push_outlives(&mut self, sup: Region<'tcx>, sub: Region<'tcx>);

    fn const_equate(&mut self, a: &'tcx Const<'tcx>, b: &'tcx Const<'tcx>);

    fn create_next_universe(&mut self) -> UniverseIndex;

    fn next_existential_region_var(
        &mut self, 
        was_placeholder: bool
    ) -> Region<'tcx>;

    fn next_placeholder_region(
        &mut self, 
        placeholder: PlaceholderRegion
    ) -> Region<'tcx>;

    fn generalize_existential(
        &mut self, 
        universe: UniverseIndex
    ) -> Region<'tcx>;

    fn normalization() -> NormalizationStrategy;

    fn forbid_inference_vars() -> bool;
}

Required methods

fn param_env(&self) -> ParamEnv<'tcx>[src]

fn push_outlives(&mut self, sup: Region<'tcx>, sub: Region<'tcx>)[src]

Push a constraint sup: sub – this constraint must be satisfied for the two types to be related. sub and sup may be regions from the type or new variables created through the delegate.

fn const_equate(&mut self, a: &'tcx Const<'tcx>, b: &'tcx Const<'tcx>)[src]

fn create_next_universe(&mut self) -> UniverseIndex[src]

Creates a new universe index. Used when instantiating placeholders.

fn next_existential_region_var(&mut self, was_placeholder: bool) -> Region<'tcx>[src]

Creates a new region variable representing a higher-ranked region that is instantiated existentially. This creates an inference variable, typically.

So e.g., if you have for<'a> fn(..) <: for<'b> fn(..), then we will invoke this method to instantiate 'a with an inference variable (though 'b would be instantiated first, as a placeholder).

fn next_placeholder_region(
    &mut self,
    placeholder: PlaceholderRegion
) -> Region<'tcx>[src]

Creates a new region variable representing a higher-ranked region that is instantiated universally. This creates a new region placeholder, typically.

So e.g., if you have for<'a> fn(..) <: for<'b> fn(..), then we will invoke this method to instantiate 'b with a placeholder region.

fn generalize_existential(&mut self, universe: UniverseIndex) -> Region<'tcx>[src]

Creates a new existential region in the given universe. This is used when handling subtyping and type variables – if we have that ?X <: Foo<'a>, for example, we would instantiate ?X with a type like Foo<'?0> where '?0 is a fresh existential variable created by this function. We would then relate Foo<'?0> with Foo<'a> (and probably add an outlives relation stating that '?0: 'a).

fn normalization() -> NormalizationStrategy[src]

Define the normalization strategy to use, eager or lazy.

fn forbid_inference_vars() -> bool[src]

Enables some optimizations if we do not expect inference variables in the RHS of the relation.

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Implementors

impl<'tcx> TypeRelatingDelegate<'tcx> for QueryTypeRelatingDelegate<'_, 'tcx>[src]

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