Simplify suggestion.

Author: reitermarkus

compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs

@@ -2142,15 +2142,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     ) -> bool {
         let tcx = self.tcx;
         let (adt, args, unwrap) = match expected.kind() {
-            // In case Option<NonZero*> is wanted, but * is provided, suggest calling new
+            // In case `Option<NonZero<T>>` is wanted, but `T` is provided, suggest calling `new`.
             ty::Adt(adt, args) if tcx.is_diagnostic_item(sym::Option, adt.did()) => {
                 let nonzero_type = args.type_at(0); // Unwrap option type.
                 let ty::Adt(adt, args) = nonzero_type.kind() else {
                     return false;
                 };
                 (adt, args, "")
             }
-            // In case `NonZero<*>` is wanted but `*` is provided, also add `.unwrap()` to satisfy types.
+            // In case `NonZero<T>` is wanted but `T` is provided, also add `.unwrap()` to satisfy types.
             ty::Adt(adt, args) => (adt, args, ".unwrap()"),
             _ => return false,
         };
@@ -2159,32 +2159,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             return false;
         }
 
-        // FIXME: This can be simplified once `NonZero<T>` is stable.
-        let coercable_types = [
-            ("NonZeroU8", tcx.types.u8),
-            ("NonZeroU16", tcx.types.u16),
-            ("NonZeroU32", tcx.types.u32),
-            ("NonZeroU64", tcx.types.u64),
-            ("NonZeroU128", tcx.types.u128),
-            ("NonZeroI8", tcx.types.i8),
-            ("NonZeroI16", tcx.types.i16),
-            ("NonZeroI32", tcx.types.i32),
-            ("NonZeroI64", tcx.types.i64),
-            ("NonZeroI128", tcx.types.i128),
-        ];
-
         let int_type = args.type_at(0);
-
-        let Some(nonzero_alias) = coercable_types.iter().find_map(|(nonzero_alias, t)| {
-            if *t == int_type && self.can_coerce(expr_ty, *t) { Some(nonzero_alias) } else { None }
-        }) else {
+        if !self.can_coerce(expr_ty, int_type) {
             return false;
-        };
+        }
 
         err.multipart_suggestion(
-            format!("consider calling `{nonzero_alias}::new`"),
+            format!("consider calling `{}::new`", sym::NonZero),
             vec![
-                (expr.span.shrink_to_lo(), format!("{nonzero_alias}::new(")),
+                (expr.span.shrink_to_lo(), format!("{}::new(", sym::NonZero)),
                 (expr.span.shrink_to_hi(), format!("){unwrap}")),
             ],
             Applicability::MaybeIncorrect,

tests/ui/mismatched_types/non_zero_assigned_something.rs

@@ -1,9 +1,9 @@
 fn main() {
-    let _: std::num::NonZeroU64 = 1;
+    let _: std::num::NonZero<u64> = 1;
     //~^ ERROR mismatched types
-    //~| HELP  consider calling `NonZeroU64::new`
+    //~| HELP  consider calling `NonZero::new`
 
-    let _: Option<std::num::NonZeroU64> = 1;
+    let _: Option<std::num::NonZero<u64>> = 1;
     //~^ ERROR mismatched types
-    //~| HELP  consider calling `NonZeroU64::new`
+    //~| HELP  consider calling `NonZero::new`
 }

tests/ui/mismatched_types/non_zero_assigned_something.stderr

@@ -1,32 +1,32 @@
 error[E0308]: mismatched types
-  --> $DIR/non_zero_assigned_something.rs:2:35
+  --> $DIR/non_zero_assigned_something.rs:2:37
    |
-LL |     let _: std::num::NonZeroU64 = 1;
-   |            --------------------   ^ expected `NonZero<u64>`, found integer
+LL |     let _: std::num::NonZero<u64> = 1;
+   |            ----------------------   ^ expected `NonZero<u64>`, found integer
    |            |
    |            expected due to this
    |
    = note: expected struct `NonZero<u64>`
                 found type `{integer}`
-help: consider calling `NonZeroU64::new`
+help: consider calling `NonZero::new`
    |
-LL |     let _: std::num::NonZeroU64 = NonZeroU64::new(1).unwrap();
-   |                                   ++++++++++++++++ ++++++++++
+LL |     let _: std::num::NonZero<u64> = NonZero::new(1).unwrap();
+   |                                     +++++++++++++ ++++++++++
 
 error[E0308]: mismatched types
-  --> $DIR/non_zero_assigned_something.rs:6:43
+  --> $DIR/non_zero_assigned_something.rs:6:45
    |
-LL |     let _: Option<std::num::NonZeroU64> = 1;
-   |            ----------------------------   ^ expected `Option<NonZero<u64>>`, found integer
+LL |     let _: Option<std::num::NonZero<u64>> = 1;
+   |            ------------------------------   ^ expected `Option<NonZero<u64>>`, found integer
    |            |
    |            expected due to this
    |
    = note: expected enum `Option<NonZero<u64>>`
               found type `{integer}`
-help: consider calling `NonZeroU64::new`
+help: consider calling `NonZero::new`
    |
-LL |     let _: Option<std::num::NonZeroU64> = NonZeroU64::new(1);
-   |                                           ++++++++++++++++ +
+LL |     let _: Option<std::num::NonZero<u64>> = NonZero::new(1);
+   |                                             +++++++++++++ +
 
 error: aborting due to 2 previous errors