Struct rustc_trait_selection::infer::at::At

pub struct At<'a, 'tcx> {
    pub infcx: &'a InferCtxt<'a, 'tcx>,
    pub cause: &'a ObligationCause<'tcx>,
    pub param_env: ParamEnv<'tcx>,
}

Fields

infcx: &'a InferCtxt<'a, 'tcx>

cause: &'a ObligationCause<'tcx>

param_env: ParamEnv<'tcx>

Trait Implementations

impl<'cx, 'tcx> AtExt<'tcx> for At<'cx, 'tcx>

fn dropck_outlives(&self, ty: Ty<'tcx>) -> InferOk<'tcx, Vec<GenericArg<'tcx>>>

Given a type ty of some value being dropped, computes a set of “kinds” (types, regions) that must be outlive the execution of the destructor. These basically correspond to data that the destructor might access. This is used during regionck to impose “outlives” constraints on any lifetimes referenced within.

The rules here are given by the “dropck” RFCs, notably #1238 and #1327. This is a fixed-point computation, where we explore all the data that will be dropped (transitively) when a value of type ty is dropped. For each type T that will be dropped and which has a destructor, we must assume that all the types/regions of T are live during the destructor, unless they are marked with a special attribute (#[may_dangle]).

impl<'cx, 'tcx> AtExt<'tcx> for At<'cx, 'tcx>

fn normalize<T>(&self, value: T) -> Result<Normalized<'tcx, T>, NoSolution> where
    T: TypeFoldable<'tcx>, 

Normalize value in the context of the inference context, yielding a resulting type, or an error if value cannot be normalized. If you don’t care about regions, you should prefer normalize_erasing_regions, which is more efficient.

If the normalization succeeds and is unambiguous, returns back the normalized value along with various outlives relations (in the form of obligations that must be discharged).

N.B., this will eventually be the main means of normalizing, but for now should be used only when we actually know that normalization will succeed, since error reporting and other details are still “under development”.