bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-ty/src/infer.rs')
-rw-r--r--crates/hir-ty/src/infer.rs34
1 files changed, 23 insertions, 11 deletions
diff --git a/crates/hir-ty/src/infer.rs b/crates/hir-ty/src/infer.rs
index 0a617dae7d..b4915dbf0f 100644
--- a/crates/hir-ty/src/infer.rs
+++ b/crates/hir-ty/src/infer.rs
@@ -13,6 +13,15 @@
//! to certain types. To record this, we use the union-find implementation from
//! the `ena` crate, which is extracted from rustc.
+mod cast;
+pub(crate) mod closure;
+mod coerce;
+mod expr;
+mod mutability;
+mod pat;
+mod path;
+pub(crate) mod unify;
+
use std::{convert::identity, ops::Index};
use chalk_ir::{
@@ -60,15 +69,8 @@ pub use coerce::could_coerce;
#[allow(unreachable_pub)]
pub use unify::could_unify;
-pub(crate) use self::closure::{CaptureKind, CapturedItem, CapturedItemWithoutTy};
-
-pub(crate) mod unify;
-mod path;
-mod expr;
-mod pat;
-mod coerce;
-pub(crate) mod closure;
-mod mutability;
+use cast::CastCheck;
+pub(crate) use closure::{CaptureKind, CapturedItem, CapturedItemWithoutTy};
/// The entry point of type inference.
pub(crate) fn infer_query(db: &dyn HirDatabase, def: DefWithBodyId) -> Arc<InferenceResult> {
@@ -508,6 +510,8 @@ pub(crate) struct InferenceContext<'a> {
diverges: Diverges,
breakables: Vec<BreakableContext>,
+ deferred_cast_checks: Vec<CastCheck>,
+
// fields related to closure capture
current_captures: Vec<CapturedItemWithoutTy>,
current_closure: Option<ClosureId>,
@@ -582,7 +586,8 @@ impl<'a> InferenceContext<'a> {
resolver,
diverges: Diverges::Maybe,
breakables: Vec::new(),
- current_captures: vec![],
+ deferred_cast_checks: Vec::new(),
+ current_captures: Vec::new(),
current_closure: None,
deferred_closures: FxHashMap::default(),
closure_dependencies: FxHashMap::default(),
@@ -594,7 +599,7 @@ impl<'a> InferenceContext<'a> {
// used this function for another workaround, mention it here. If you really need this function and believe that
// there is no problem in it being `pub(crate)`, remove this comment.
pub(crate) fn resolve_all(self) -> InferenceResult {
- let InferenceContext { mut table, mut result, .. } = self;
+ let InferenceContext { mut table, mut result, deferred_cast_checks, .. } = self;
// Destructure every single field so whenever new fields are added to `InferenceResult` we
// don't forget to handle them here.
let InferenceResult {
@@ -622,6 +627,13 @@ impl<'a> InferenceContext<'a> {
table.fallback_if_possible();
+ // Comment from rustc:
+ // Even though coercion casts provide type hints, we check casts after fallback for
+ // backwards compatibility. This makes fallback a stronger type hint than a cast coercion.
+ for cast in deferred_cast_checks {
+ cast.check(&mut table);
+ }
+
// FIXME resolve obligations as well (use Guidance if necessary)
table.resolve_obligations_as_possible();