+
+fn is_plain_default(arg_path: &Expr<'_>) -> bool {
+ // we need to match the actual path so we don't match e.g. "u8::default"
+ if let ExprKind::Path(QPath::Resolved(None, path)) = &arg_path.kind {
+ // avoid generic parameters
+ match_path(path, &paths::DEFAULT_TRAIT_METHOD) && path.segments.iter().all(|seg| seg.args.is_none())
+ } else {
+ false
+ }
+}
+
+fn is_vec_expn(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+ macro_backtrace(expr.span)
+ .next()
+ .map_or(false, |call| cx.tcx.is_diagnostic_item(sym::vec_macro, call.def_id))
+}
+
+#[derive(Default)]
+struct InferVisitor(bool);
+
+impl<'tcx> Visitor<'tcx> for InferVisitor {
+ fn visit_ty(&mut self, t: &rustc_hir::Ty<'_>) {
+ self.0 |= matches!(t.kind, TyKind::Infer | TyKind::OpaqueDef(..) | TyKind::TraitObject(..));
+ if !self.0 {
+ walk_ty(self, t);
+ }
+ }
+}
+
+fn given_type(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+ match get_parent_node(cx.tcx, expr.hir_id) {
+ Some(Node::Local(Local { ty: Some(ty), .. })) => {
+ let mut v = InferVisitor::default();
+ v.visit_ty(ty);
+ !v.0
+ },
+ Some(
+ Node::Expr(Expr {
+ kind: ExprKind::Call(path, args),
+ ..
+ }) | Node::Block(Block {
+ expr:
+ Some(Expr {
+ kind: ExprKind::Call(path, args),
+ ..
+ }),
+ ..
+ }),
+ ) => {
+ if let Some(index) = args.iter().position(|arg| arg.hir_id == expr.hir_id) &&
+ let Some(sig) = expr_sig(cx, path) &&
+ let Some(input) = sig.input(index)
+ {
+ input.no_bound_vars().is_some()
+ } else {
+ false
+ }
+ },
+ _ => false,
+ }
+}