Merge #8327

8327: Move `Ty` creation methods out of `Ty` (Chalk move preparation) r=flodiebold a=flodiebold

When we'll move to using `chalk_ir::Ty` (#8313), we won't be able to have our own inherent methods on `Ty` anymore, so we need to move the helpers elsewhere.
This adds a `TyBuilder` that allows easily constructing `Ty` and related types (`TraitRef`, `ProjectionTy`, `Substitution`). It also replaces `SubstsBuilder`. `TyBuilder` can construct different things based on its type parameter; e.g. if it has an `AdtId`, we're constructing an ADT type, but if it has a `TraitId`, we're constructing a `TraitRef`. The common thing for all of them is that we need to build a `Substitution`, so the API stays the same for all of them except at the beginning and end.

We also use `TyBuilder` to house various one-shot methods for constructing types, e.g. `TyBuilder::unit()`.

Co-authored-by: Florian Diebold <[email protected]>

1 files changed, 2 insertions, 2 deletions

diff --git a/crates/hir_ty/src/diagnostics/expr.rs b/crates/hir_ty/src/diagnostics/expr.rs
index ad1259b34..8169b759f 100644
--- a/crates/hir_ty/src/diagnostics/expr.rs
+++ b/crates/hir_ty/src/diagnostics/expr.rs
@@ -15,7 +15,7 @@ use crate::{
         MissingPatFields, RemoveThisSemicolon,
     },
     utils::variant_data,
-    AdtId, InferenceResult, Interner, Ty, TyKind,
+    AdtId, InferenceResult, Interner, TyExt, TyKind,
 };
 
 pub(crate) use hir_def::{
@@ -423,7 +423,7 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
             None => return,
         };
 
-        if mismatch.actual != Ty::unit() || mismatch.expected != *possible_tail_ty {
+        if !mismatch.actual.is_unit() || mismatch.expected != *possible_tail_ty {
             return;
         }