rust-clippy/tests/ui/needless_pass_by_value_proc_macro.rs

#![feature(plugin)]
#![plugin(clippy)]
#![crate_type = "proc-macro"]
#![deny(needless_pass_by_value)]

extern crate proc_macro;

use proc_macro::TokenStream;

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