fn hash_substructure(cx: &mut ExtCtxt, trait_span: Span, substr: &Substructure) -> P<Expr> {
let state_expr = match substr.nonself_args {
[ref state_expr] => state_expr,
- _ => cx.span_bug(trait_span, "incorrect number of arguments in `deriving(Hash)`")
+ _ => cx.span_bug(trait_span, "incorrect number of arguments in `derive(Hash)`")
};
let hash_ident = substr.method_ident;
let call_hash = |&: span, thing_expr| {
fs
}
- _ => cx.span_bug(trait_span, "impossible substructure in `deriving(Hash)`")
+ _ => cx.span_bug(trait_span, "impossible substructure in `derive(Hash)`")
};
for &FieldInfo { ref self_, span, .. } in fields.iter() {
stmts.push(call_hash(span, self_.clone()));
}
- if stmts.len() == 0 {
- cx.span_bug(trait_span, "#[derive(Hash)] needs at least one field");
- }
-
cx.expr_block(cx.block(trait_span, stmts, None))
}
--- /dev/null
+// Copyright 2015 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.
+
+use std::hash::{SipHasher, hash};
+
+#[derive(Hash)]
+struct Empty;
+
+pub fn main() {
+ assert!(hash::<_, SipHasher>(&Empty) == hash::<_, SipHasher>(&Empty));
+}