Rollup merge of #128110 - veera-sivarajan:bugfix-80173, r=cjgillot

Suggest Replacing Comma with Semicolon in Incorrect Repeat Expressions

Fixes #80173

This PR detects typos in repeat expressions like `["_", 10]` and `vec![String::new(), 10]` and suggests replacing comma with semicolon.

Also, improves code in other place by adding doc comments and making use of a helper function to check if a type implements `Clone`.

References:
1. For `vec![T; N]`: https://doc.rust-lang.org/std/macro.vec.html
2. For `[T; N]`: https://doc.rust-lang.org/std/primitive.array.html

1 files changed, 13 insertions, 1 deletions

diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs
index 92b3632c8ac..2980964898c 100644
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/compiler/rustc_middle/src/ty/sty.rs
@@ -27,7 +27,7 @@ use crate::infer::canonical::Canonical;
 use crate::ty::InferTy::*;
 use crate::ty::{
     self, AdtDef, BoundRegionKind, Discr, GenericArg, GenericArgs, GenericArgsRef, List, ParamEnv,
-    Region, Ty, TyCtxt, TypeFlags, TypeSuperVisitable, TypeVisitable, TypeVisitor,
+    Region, Ty, TyCtxt, TypeFlags, TypeSuperVisitable, TypeVisitable, TypeVisitor, UintTy,
 };
 
 // Re-export and re-parameterize some `I = TyCtxt<'tcx>` types here
@@ -1017,6 +1017,18 @@ impl<'tcx> Ty<'tcx> {
         }
     }
 
+    /// Check if type is an `usize`.
+    #[inline]
+    pub fn is_usize(self) -> bool {
+        matches!(self.kind(), Uint(UintTy::Usize))
+    }
+
+    /// Check if type is an `usize` or an integral type variable.
+    #[inline]
+    pub fn is_usize_like(self) -> bool {
+        matches!(self.kind(), Uint(UintTy::Usize) | Infer(IntVar(_)))
+    }
+
     #[inline]
     pub fn is_never(self) -> bool {
         matches!(self.kind(), Never)