From 91992aaef2c6e944f99f61ae7591a30a350d3b5e Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume1.gomez@gmail.com>
Date: Sat, 10 Apr 2021 16:47:03 +0200
Subject: [PATCH] Ensure that README code example is up to date

---
 Cargo.toml |  1 +
 README.md  | 10 +++++-----
 src/lib.rs |  7 +++++++
 3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index d29b93db67..a4361c3473 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -41,6 +41,7 @@ unicode-xid = "0.2"
 
 [dev-dependencies]
 anyhow = "1.0"
+doc-comment = "0.3"
 flate2 = "1.0"
 insta = "1.0"
 rayon = "1.0"
diff --git a/README.md b/README.md
index 12b5f45b3d..1617b338e4 100644
--- a/README.md
+++ b/README.md
@@ -120,7 +120,7 @@ pub trait HeapSize {
 The derive macro allows users to write `#[derive(HeapSize)]` on data structures
 in their program.
 
-```rust
+```rust,ignore
 #[derive(HeapSize)]
 struct Demo<'a, T: ?Sized> {
     a: Box<T>,
@@ -138,7 +138,7 @@ The token-based procedural macro API provides great control over where the
 compiler's error messages are displayed in user code. Consider the error the
 user sees if one of their field types does not implement `HeapSize`.
 
-```rust
+```rust,ignore
 #[derive(HeapSize)]
 struct Broken {
     ok: String,
@@ -150,7 +150,7 @@ By tracking span information all the way through the expansion of a procedural
 macro as shown in the `heapsize` example, token-based macros in Syn are able to
 trigger errors that directly pinpoint the source of the problem.
 
-```
+```text
 error[E0277]: the trait bound `std::thread::Thread: HeapSize` is not satisfied
  --> src/main.rs:7:5
   |
@@ -171,7 +171,7 @@ Syn's parsing API.
 The example reimplements the popular `lazy_static` crate from crates.io as a
 procedural macro.
 
-```
+```rust,ignore
 lazy_static! {
     static ref USERNAME: Regex = Regex::new("^[a-z0-9_-]{3,16}$").unwrap();
 }
@@ -180,7 +180,7 @@ lazy_static! {
 The implementation shows how to trigger custom warnings and error messages on
 the macro input.
 
-```
+```text
 warning: come on, pick a more creative name
   --> src/main.rs:10:16
    |
diff --git a/src/lib.rs b/src/lib.rs
index ea0c6dde79..68c45327dd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -306,6 +306,13 @@ extern crate unicode_xid;
 #[cfg(feature = "printing")]
 extern crate quote;
 
+#[cfg(doctest)]
+#[macro_use]
+extern crate doc_comment;
+
+#[cfg(doctest)]
+doctest!("../README.md");
+
 #[macro_use]
 mod macros;