Aaron Hill 93ab12eeab Improve cause information for NLL higher-ranked errors ... This PR has several interconnected pieces: 1. In some of the NLL region error code, we now pass around an `ObligationCause`, instead of just a plain `Span`. This gets forwarded into `fulfill_cx.register_predicate_obligation` during error reporting. 2. The general InferCtxt error reporting code is extended to handle `ObligationCauseCode::BindingObligation` 3. A new enum variant `ConstraintCategory::Predicate` is added. We try to avoid using this as the 'best blame constraint' - instead, we use it to enhance the `ObligationCause` of the `BlameConstraint` that we do end up choosing. As a result, several NLL error messages now contain the same "the lifetime requirement is introduced here" message as non-NLL errors. Having an `ObligationCause` available will likely prove useful for future improvements to NLL error messages.		2021-09-27 10:23:45 -05:00
..
chalk	make unevaluated const substs optional	2021-08-26 11:00:30 +02:00
dropck_outlives.rs
evaluate_obligation.rs
implied_outlives_bounds.rs	introduce a Coerce predicate	2021-08-19 17:28:24 -04:00
lib.rs	Improve cause information for NLL higher-ranked errors	2021-09-27 10:23:45 -05:00
normalize_erasing_regions.rs	introduce a Coerce predicate	2021-08-19 17:28:24 -04:00
normalize_projection_ty.rs
type_op.rs	Improve cause information for NLL higher-ranked errors	2021-09-27 10:23:45 -05:00