if_chain! {
// Check if item is a method, called to_string and has a parameter 'self'
if let ImplItemKind::Fn(ref signature, _) = impl_item.kind;
- if impl_item.ident.name.as_str() == "to_string";
+ if impl_item.ident.name == sym::to_string;
let decl = &signature.decl;
if decl.implicit_self.has_implicit_self();
if decl.inputs.len() == 1;