Move 'is_isize_or_usize' to clippy_utils

clippy_utils/src/lib.rs

@@ -72,7 +72,7 @@ use rustc_lint::{LateContext, Level, Lint, LintContext};
 use rustc_middle::hir::exports::Export;
 use rustc_middle::hir::map::Map;
 use rustc_middle::ty::subst::{GenericArg, GenericArgKind};
-use rustc_middle::ty::{self, layout::IntegerExt, DefIdTree, Ty, TyCtxt, TypeFoldable};
+use rustc_middle::ty::{self, layout::IntegerExt, DefIdTree, IntTy, Ty, TyCtxt, TypeFoldable, UintTy};
 use rustc_semver::RustcVersion;
 use rustc_session::Session;
 use rustc_span::hygiene::{self, ExpnKind, MacroKind};
@@ -262,6 +262,11 @@ pub fn is_ty_param_diagnostic_item(
     }
 }
 
+/// Return `true` if the passed `typ` is `isize` or `usize`.
+pub fn is_isize_or_usize(typ: Ty<'_>) -> bool {
+    matches!(typ.kind(), ty::Int(IntTy::Isize) | ty::Uint(UintTy::Usize))
+}
+
 /// Checks if the method call given in `expr` belongs to the given trait.
 pub fn match_trait_method(cx: &LateContext<'_>, expr: &Expr<'_>, path: &[&str]) -> bool {
     let def_id = cx.typeck_results().type_dependent_def_id(expr.hir_id).unwrap();