Replace contains_ty(..) with Ty::contains(..)

This removes some code we don't need and the method syntax is
also more readable IMO.

Author: Michael Wright

clippy_lints/src/dereference.rs

@@ -1,7 +1,7 @@
 use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_hir_and_then};
 use clippy_utils::source::{snippet_with_applicability, snippet_with_context};
 use clippy_utils::sugg::has_enclosing_paren;
-use clippy_utils::ty::{contains_ty, expr_sig, is_copy, peel_mid_ty_refs, ty_sig, variant_of_res};
+use clippy_utils::ty::{expr_sig, is_copy, peel_mid_ty_refs, ty_sig, variant_of_res};
 use clippy_utils::{fn_def_id, get_parent_expr, is_lint_allowed, meets_msrv, msrvs, path_to_local, walk_to_expr_usage};
 use rustc_ast::util::parser::{PREC_POSTFIX, PREC_PREFIX};
 use rustc_data_structures::fx::FxIndexMap;
@@ -1158,7 +1158,7 @@ fn replace_types<'tcx>(
             .inputs_and_output
             .iter()
             .enumerate()
-            .all(|(i, ty)| (replaced.is_empty() && i == arg_index) || !contains_ty(ty, param_ty.to_ty(cx.tcx)))
+            .all(|(i, ty)| (replaced.is_empty() && i == arg_index) || !ty.contains(param_ty.to_ty(cx.tcx)))
         {
             return false;
         }

clippy_lints/src/escape.rs

@@ -1,5 +1,4 @@
 use clippy_utils::diagnostics::span_lint_hir;
-use clippy_utils::ty::contains_ty;
 use rustc_hir::intravisit;
 use rustc_hir::{self, AssocItemKind, Body, FnDecl, HirId, HirIdSet, Impl, ItemKind, Node, Pat, PatKind};
 use rustc_infer::infer::TyCtxtInferExt;
@@ -166,7 +165,7 @@ impl<'a, 'tcx> Delegate<'tcx> for EscapeDelegate<'a, 'tcx> {
                 // skip if there is a `self` parameter binding to a type
                 // that contains `Self` (i.e.: `self: Box<Self>`), see #4804
                 if let Some(trait_self_ty) = self.trait_self_ty {
-                    if map.name(cmt.hir_id) == kw::SelfLower && contains_ty(cmt.place.ty(), trait_self_ty) {
+                    if map.name(cmt.hir_id) == kw::SelfLower && cmt.place.ty().contains(trait_self_ty) {
                         return;
                     }
                 }

clippy_lints/src/methods/mod.rs

@@ -99,7 +99,7 @@ mod zst_offset;
 use bind_instead_of_map::BindInsteadOfMap;
 use clippy_utils::consts::{constant, Constant};
 use clippy_utils::diagnostics::{span_lint, span_lint_and_help};
-use clippy_utils::ty::{contains_adt_constructor, contains_ty, implements_trait, is_copy, is_type_diagnostic_item};
+use clippy_utils::ty::{contains_adt_constructor, implements_trait, is_copy, is_type_diagnostic_item};
 use clippy_utils::{
     contains_return, get_trait_def_id, is_trait_method, iter_input_pats, meets_msrv, msrvs, paths, return_ty,
 };
@@ -3242,7 +3242,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
                 if contains_adt_constructor(ret_ty, self_adt) {
                     return;
                 }
-            } else if contains_ty(ret_ty, self_ty) {
+            } else if ret_ty.contains(self_ty) {
                 return;
             }
 
@@ -3260,7 +3260,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
                             if contains_adt_constructor(assoc_ty, self_adt) {
                                 return;
                             }
-                        } else if contains_ty(assoc_ty, self_ty) {
+                        } else if assoc_ty.contains(self_ty) {
                             return;
                         }
                     }
@@ -3309,7 +3309,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
             if let TraitItemKind::Fn(_, _) = item.kind;
             let ret_ty = return_ty(cx, item.hir_id());
             let self_ty = TraitRef::identity(cx.tcx, item.def_id.to_def_id()).self_ty().skip_binder();
-            if !contains_ty(ret_ty, self_ty);
+            if !ret_ty.contains(self_ty);
 
             then {
                 span_lint(

clippy_lints/src/methods/unnecessary_to_owned.rs

@@ -3,8 +3,7 @@ use super::unnecessary_iter_cloned::{self, is_into_iter};
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::snippet_opt;
 use clippy_utils::ty::{
-    contains_ty, get_associated_type, get_iterator_item_ty, implements_trait, is_copy, is_type_diagnostic_item,
-    peel_mid_ty_refs,
+    get_associated_type, get_iterator_item_ty, implements_trait, is_copy, is_type_diagnostic_item, peel_mid_ty_refs,
 };
 use clippy_utils::{fn_def_id, get_parent_expr, is_diag_item_method, is_diag_trait_item};
 use clippy_utils::{meets_msrv, msrvs};
@@ -304,7 +303,7 @@ fn check_other_call_arg<'tcx>(
         // (https://github.com/rust-lang/rust-clippy/issues/8507).
         if (n_refs == 0 && !receiver_ty.is_ref())
             || trait_predicate.def_id() != as_ref_trait_id
-            || !contains_ty(fn_sig.output(), input);
+            || !fn_sig.output().contains(input);
         if let Some(receiver_snippet) = snippet_opt(cx, receiver.span);
         then {
             span_lint_and_sugg(

clippy_lints/src/self_named_constructors.rs

@@ -1,6 +1,6 @@
 use clippy_utils::diagnostics::span_lint;
 use clippy_utils::return_ty;
-use clippy_utils::ty::{contains_adt_constructor, contains_ty};
+use clippy_utils::ty::contains_adt_constructor;
 use rustc_hir::{Impl, ImplItem, ImplItemKind, ItemKind, Node};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
@@ -66,7 +66,7 @@ impl<'tcx> LateLintPass<'tcx> for SelfNamedConstructors {
             if !contains_adt_constructor(ret_ty, self_adt) {
                 return;
             }
-        } else if !contains_ty(ret_ty, self_ty) {
+        } else if !ret_ty.contains(self_ty) {
             return;
         }
 

clippy_utils/src/ty.rs

@@ -43,14 +43,6 @@ pub fn can_partially_move_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool
     }
 }
 
-/// Walks into `ty` and returns `true` if any inner type is the same as `other_ty`
-pub fn contains_ty<'tcx>(ty: Ty<'tcx>, other_ty: Ty<'tcx>) -> bool {
-    ty.walk().any(|inner| match inner.unpack() {
-        GenericArgKind::Type(inner_ty) => other_ty == inner_ty,
-        GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false,
-    })
-}
-
 /// Walks into `ty` and returns `true` if any inner type is an instance of the given adt
 /// constructor.
 pub fn contains_adt_constructor<'tcx>(ty: Ty<'tcx>, adt: AdtDef<'tcx>) -> bool {