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/snippets/Cwise_arg.cpp b/doc/snippets/Cwise_arg.cpp
new file mode 100644
index 0000000..3f45133
--- /dev/null
+++ b/doc/snippets/Cwise_arg.cpp
@@ -0,0 +1,3 @@
+ArrayXcf v = ArrayXcf::Random(3);
+cout << v << endl << endl;
+cout << arg(v) << endl;