diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index 50e3483fb15d2..44b7cc8d18175 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -5175,7 +5175,15 @@ impl<'a> Parser<'a> { if self.eat(&token::OpenDelim(token::Brace)) { // Parse a struct variant. all_nullary = false; - kind = StructVariantKind(self.parse_struct_def()); + let start_span = self.span; + let struct_def = self.parse_struct_def(); + if struct_def.fields.len() == 0 { + self.span_err(start_span, + format!("unit-like struct variant should be written \ + without braces, as `{},`", + token::get_ident(ident)).as_slice()); + } + kind = StructVariantKind(struct_def); } else if self.token == token::OpenDelim(token::Paren) { all_nullary = false; let arg_tys = self.parse_enum_variant_seq( diff --git a/src/test/compile-fail/struct-variant-no-fields.rs b/src/test/compile-fail/struct-variant-no-fields.rs new file mode 100644 index 0000000000000..41dbbeefc0a60 --- /dev/null +++ b/src/test/compile-fail/struct-variant-no-fields.rs @@ -0,0 +1,13 @@ +// Copyright 2014 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. + +enum Foo { + Bar {} //~ ERROR unit-like struct variant should be written without braces, as `Bar,` +}