macro_rules! maybe_whole_expr (
($p:expr) => (
{
- let mut maybe_path = match ($p).token {
- INTERPOLATED(token::NtPath(ref pt)) => Some((**pt).clone()),
- _ => None,
- };
- let found = match ($p).token {
+ let found = match $p.token {
INTERPOLATED(token::NtExpr(e)) => {
Some(e)
}
INTERPOLATED(token::NtPath(_)) => {
- let pt = maybe_path.take_unwrap();
- Some($p.mk_expr(($p).span.lo, ($p).span.hi, ExprPath(pt)))
+ // FIXME: The following avoids an issue with lexical borrowck scopes,
+ // but the clone is unfortunate.
+ let pt = match $p.token {
+ INTERPOLATED(token::NtPath(ref pt)) => (**pt).clone(),
+ _ => unreachable!()
+ };
+ Some($p.mk_expr($p.span.lo, $p.span.hi, ExprPath(pt)))
+ }
+ INTERPOLATED(token::NtBlock(b)) => {
+ Some($p.mk_expr($p.span.lo, $p.span.hi, ExprBlock(b)))
}
_ => None
};
--- /dev/null
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(macro_rules)]
+
+macro_rules! do_block{
+ ($val:block) => {$val}
+}
+
+fn main() {
+ let s;
+ do_block!({ s = "it works!"; });
+ assert_eq!(s, "it works!");
+}