rust-clippy/tests/ui/needless_pass_by_value_proc_macro.rs

// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

#![crate_type = "proc-macro"]
#![warn(clippy::needless_pass_by_value)]

extern crate proc_macro;

use proc_macro::TokenStream;

#[proc_macro_derive(Foo)]
pub fn foo(_input: TokenStream) -> TokenStream {
    unimplemented!()
}