// Copyright 2017 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. macro_rules! is_plainly_printable { ($i: ident) => { $i as u32 < 0 //~ `<` is interpreted as a start of generic arguments }; } fn main() { let c = 'a'; is_plainly_printable!(c); }