Squashed 'third_party/eigen/' changes from 61d72f6..cf794d3


Change-Id: I9b814151b01f49af6337a8605d0c42a3a1ed4c72
git-subtree-dir: third_party/eigen
git-subtree-split: cf794d3b741a6278df169e58461f8529f43bce5d
diff --git a/doc/TopicAssertions.dox b/doc/TopicAssertions.dox
index 4ead401..c8b4d84 100644
--- a/doc/TopicAssertions.dox
+++ b/doc/TopicAssertions.dox
@@ -16,7 +16,7 @@
 #include <stdexcept>
 #undef eigen_assert
 #define eigen_assert(x) \
-  if (!x) { throw (std::runtime_error("Put your message here")); }
+  if (!(x)) { throw (std::runtime_error("Put your message here")); }
 \endcode
 
 \subsection DisableAssert Disabling assertions