Update books
diff --git a/src/doc/book b/src/doc/book
index 7ddc464..871416b 160000
--- a/src/doc/book
+++ b/src/doc/book
@@ -1 +1 @@
-Subproject commit 7ddc46460f09a5cd9bd2a620565bdc20b3315ea9
+Subproject commit 871416b85c1a73717d65d6f4a9ea29e5aef3db0e
diff --git a/src/doc/rust-by-example b/src/doc/rust-by-example
index e76be6b..67cfbf3 160000
--- a/src/doc/rust-by-example
+++ b/src/doc/rust-by-example
@@ -1 +1 @@
-Subproject commit e76be6b2dc84c6a992e186157efe29d625e29b94
+Subproject commit 67cfbf31df880728dcf7cb35b15b028ec92caf31
