WIP

crates/hir-ty/src/consteval/tests.rs

@@ -186,7 +186,13 @@ fn floating_point() {
 
 #[test]
 fn casts() {
-    check_number(r#"const GOAL: usize = 12 as *const i32 as usize"#, 12);
+    check_number(
+        r#"
+    //- minicore: sized
+    const GOAL: usize = 12 as *const i32 as usize
+        "#,
+        12,
+    );
     check_number(
         r#"
     //- minicore: coerce_unsized, index, slice
@@ -204,7 +210,7 @@ fn casts() {
         r#"
     //- minicore: coerce_unsized, index, slice
     const GOAL: i16 = {
-        let a = &mut 5;
+        let a = &mut 5_i16;
         let z = a as *mut _;
         unsafe { *z }
     };
@@ -244,7 +250,13 @@ fn casts() {
         "#,
         4,
     );
-    check_number(r#"const GOAL: i32 = -12i8 as i32"#, -12);
+    check_number(
+        r#"
+    //- minicore: sized
+    const GOAL: i32 = -12i8 as i32
+        "#,
+        -12,
+    );
 }
 
 #[test]
@@ -2422,6 +2434,7 @@ fn statics() {
 fn extern_weak_statics() {
     check_number(
         r#"
+    //- minicore: sized
     extern "C" {
         #[linkage = "extern_weak"]
         static __dso_handle: *mut u8;
@@ -2716,6 +2729,7 @@ fn const_trait_assoc() {
     );
     check_number(
         r#"
+    //- minicore: sized
     struct S<T>(*mut T);
 
     trait MySized: Sized {

crates/hir-ty/src/consteval/tests/intrinsics.rs

@@ -311,6 +311,7 @@ fn saturating() {
 fn allocator() {
     check_number(
         r#"
+        //- minicore: sized
         extern "Rust" {
             #[rustc_allocator]
             fn __rust_alloc(size: usize, align: usize) -> *mut u8;

crates/hir-ty/src/infer.rs

@@ -254,6 +254,10 @@ pub enum InferenceDiagnostic {
         expr: ExprId,
         expected: Ty,
     },
+    // CastToUnsized {
+    //     expr: ExprId,
+    //     cast_ty: Ty,
+    // },
 }
 
 /// A mismatch between an expected and an inferred type.
@@ -703,7 +707,15 @@ impl<'a> InferenceContext<'a> {
         // 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);
+            let expr = cast.expr();
+            match cast.check(&mut table) {
+                Ok(Some(adjustments)) => {
+                    // Using this causes some mir lowerings failures
+                    // expr_adjustments.insert(expr, adjustments);
+                }
+                Ok(None) => (),
+                Err(diag) => diagnostics.push(diag),
+            }
         }
 
         // FIXME resolve obligations as well (use Guidance if necessary)