bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-ty/src/infer/autoderef.rs')
-rw-r--r--crates/hir-ty/src/infer/autoderef.rs54
1 files changed, 54 insertions, 0 deletions
diff --git a/crates/hir-ty/src/infer/autoderef.rs b/crates/hir-ty/src/infer/autoderef.rs
new file mode 100644
index 0000000000..77b1ae6a94
--- /dev/null
+++ b/crates/hir-ty/src/infer/autoderef.rs
@@ -0,0 +1,54 @@
+//! Autoderef helpers for inference.
+
+use std::iter;
+
+use crate::{
+ Adjust, Adjustment, OverloadedDeref,
+ autoderef::{Autoderef, AutoderefKind},
+ infer::unify::InferenceTable,
+ next_solver::{
+ Ty,
+ infer::{InferOk, traits::PredicateObligations},
+ mapping::NextSolverToChalk,
+ },
+};
+
+impl<'db> InferenceTable<'db> {
+ pub(crate) fn autoderef(&mut self, base_ty: Ty<'db>) -> Autoderef<'_, 'db> {
+ Autoderef::new(self, base_ty)
+ }
+}
+
+impl<'db> Autoderef<'_, 'db> {
+ /// Returns the adjustment steps.
+ pub(crate) fn adjust_steps(mut self) -> Vec<Adjustment> {
+ let infer_ok = self.adjust_steps_as_infer_ok();
+ self.table.register_infer_ok(infer_ok)
+ }
+
+ pub(crate) fn adjust_steps_as_infer_ok(&mut self) -> InferOk<'db, Vec<Adjustment>> {
+ let steps = self.steps();
+ if steps.is_empty() {
+ return InferOk { obligations: PredicateObligations::new(), value: vec![] };
+ }
+
+ let targets = steps.iter().skip(1).map(|&(ty, _)| ty).chain(iter::once(self.final_ty()));
+ let steps: Vec<_> = steps
+ .iter()
+ .map(|&(_source, kind)| {
+ if let AutoderefKind::Overloaded = kind {
+ Some(OverloadedDeref(Some(chalk_ir::Mutability::Not)))
+ } else {
+ None
+ }
+ })
+ .zip(targets)
+ .map(|(autoderef, target)| Adjustment {
+ kind: Adjust::Deref(autoderef),
+ target: target.to_chalk(self.table.interner),
+ })
+ .collect();
+
+ InferOk { obligations: self.take_obligations(), value: steps }
+ }
+}