rust/src/test/ui/macros/nonterminal-matching.rs
2018-05-13 19:51:32 +00:00

37 lines
1.1 KiB
Rust

// Copyright 2018 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 <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.
// Check that we are refusing to match on complex nonterminals for which tokens are
// unavailable and we'd have to go through AST comparisons.
#![feature(decl_macro)]
macro simple_nonterminal($nt_ident: ident, $nt_lifetime: lifetime, $nt_tt: tt) {
macro n(a $nt_ident b $nt_lifetime c $nt_tt d) {
struct S;
}
n!(a $nt_ident b $nt_lifetime c $nt_tt d);
}
macro complex_nonterminal($nt_item: item) {
macro n(a $nt_item b) {
struct S;
}
n!(a $nt_item b); //~ ERROR no rules expected the token `enum E { }`
}
simple_nonterminal!(a, 'a, (x, y, z)); // OK
complex_nonterminal!(enum E {});
fn main() {}