From e0412f18fd444476a0bbd7c675e07ee21b5b76c9 Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Mon, 12 Jun 2017 22:26:26 +0200
Subject: [PATCH] Fix compilation of streaming nested Array, i.e., cout <<
 Array<Array<>> (grafted from e43d8fe9d778929051e740ef9a9143b6a2f26482 )

---
 Eigen/src/Core/NumTraits.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Eigen/src/Core/NumTraits.h b/Eigen/src/Core/NumTraits.h
index dd61195bc..daf489878 100644
--- a/Eigen/src/Core/NumTraits.h
+++ b/Eigen/src/Core/NumTraits.h
@@ -215,6 +215,8 @@ struct NumTraits<Array<Scalar, Rows, Cols, Options, MaxRows, MaxCols> >
   static inline RealScalar epsilon() { return NumTraits<RealScalar>::epsilon(); }
   EIGEN_DEVICE_FUNC
   static inline RealScalar dummy_precision() { return NumTraits<RealScalar>::dummy_precision(); }
+
+  static inline int digits10() { return NumTraits<Scalar>::digits10(); }
 };
 
 template<> struct NumTraits<std::string>