From d3ae2eb58ea2f96aa52b53d9171111b176b611eb Mon Sep 17 00:00:00 2001
From: Corey Farwell <coreyf@rwell.org>
Date: Sun, 12 Mar 2017 01:12:29 -0500
Subject: [PATCH] Rust unstable book: basic desc and example for
 `concat_idents`.

---
 src/doc/unstable-book/src/concat-idents.md | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/doc/unstable-book/src/concat-idents.md b/src/doc/unstable-book/src/concat-idents.md
index c9a48293dba68..ecfd34a22e5cc 100644
--- a/src/doc/unstable-book/src/concat-idents.md
+++ b/src/doc/unstable-book/src/concat-idents.md
@@ -6,5 +6,17 @@ The tracking issue for this feature is: [#29599]
 
 ------------------------
 
+The `concat_idents` feature adds a macro for concatenating multiple identifiers
+into one identifier.
 
+## Examples
 
+```rust
+#![feature(concat_idents)]
+
+fn main() {
+    fn foobar() -> u32 { 23 }
+    let f = concat_idents!(foo, bar);
+    assert_eq!(f(), 23);
+}
+```
\ No newline at end of file