Rollup merge of #155007 - josetorrs:rename-is-impl-trait, r=WaffleLapkin,Kivooeo

renaming method is_impl_trait to is_opaque

Completing one of the tasks mentioned in this issue: https://github.com/rust-lang/rust/issues/154941

r? @WaffleLapkin

compiler/rustc_hir_analysis/src/check/check.rs

@@ -2167,7 +2167,7 @@ fn visit_ty(&mut self, t: Ty<'tcx>) {
                 for def_id in visitor.opaques {
                     let ty_span = tcx.def_span(def_id);
                     if !seen.contains(&ty_span) {
-                        let descr = if ty.is_impl_trait() { "opaque " } else { "" };
+                        let descr = if ty.is_opaque() { "opaque " } else { "" };
                         err.span_label(ty_span, format!("returning this {descr}type `{ty}`"));
                         seen.insert(ty_span);
                     }

compiler/rustc_hir_typeck/src/expr_use_visitor.rs

@@ -1462,7 +1462,7 @@ fn cat_projection(
                 && self
                     .cx
                     .structurally_resolve_type(self.cx.tcx().hir_span(base_place.hir_id), place_ty)
-                    .is_impl_trait()
+                    .is_opaque()
             {
                 projections.push(Projection { kind: ProjectionKind::OpaqueCast, ty: node_ty });
             }

compiler/rustc_lint/src/traits.rs

@@ -97,7 +97,7 @@ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'tcx>) {
             let def_id = trait_predicate.trait_ref.def_id;
             if cx.tcx.is_lang_item(def_id, LangItem::Drop) {
                 // Explicitly allow `impl Drop`, a drop-guards-as-unnameable-type pattern.
-                if trait_predicate.trait_ref.self_ty().is_impl_trait() {
+                if trait_predicate.trait_ref.self_ty().is_opaque() {
                     continue;
                 }
                 let Some(def_id) = cx.tcx.get_diagnostic_item(sym::needs_drop) else { return };

compiler/rustc_middle/src/ty/sty.rs

@@ -1594,7 +1594,7 @@ pub fn is_fn_ptr(self) -> bool {
     }
 
     #[inline]
-    pub fn is_impl_trait(self) -> bool {
+    pub fn is_opaque(self) -> bool {
         matches!(self.kind(), Alias(ty::AliasTy { kind: ty::Opaque { .. }, .. }))
     }
 

src/tools/clippy/clippy_lints/src/methods/unnecessary_fold.rs

@@ -41,7 +41,7 @@ fn needs_turbofish<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'tcx>) -> bool
                 if !fn_return_ty
                     .skip_binder()
                     .walk()
-                    .any(|generic| generic.as_type().is_some_and(Ty::is_impl_trait)) =>
+                    .any(|generic| generic.as_type().is_some_and(Ty::is_opaque)) =>
             {
                 return false;
             },

src/tools/clippy/clippy_lints/src/missing_const_for_fn.rs

@@ -207,7 +207,7 @@ fn fn_inputs_has_impl_trait_ty(cx: &LateContext<'_>, def_id: LocalDefId) -> bool
     inputs.iter().any(|input| {
         matches!(
             input.kind(),
-            &ty::Alias(ty::AliasTy { kind: ty::Free{def_id} , ..}) if cx.tcx.type_of(def_id).skip_binder().is_impl_trait()
+            &ty::Alias(ty::AliasTy { kind: ty::Free{def_id} , ..}) if cx.tcx.type_of(def_id).skip_binder().is_opaque()
         )
     })
 }