Add numeric_limits min and max for bool

This will allow (among other things) computation of argmax and argmin of bool tensors

Eigen/src/Core/NumTraits.h

@@ -284,6 +284,8 @@ private:
 // Empty specialization for void to allow template specialization based on NumTraits<T>::Real with T==void and SFINAE.
 template<> struct NumTraits<void> {};
 
+template<> NumTraits<bool> : GenericNumTraits<bool> {};
+
 } // end namespace Eigen
 
 #endif // EIGEN_NUMTRAITS_H

Eigen/src/Core/util/Meta.h

@@ -359,6 +359,15 @@ template<> struct numeric_limits<unsigned long long>
   EIGEN_DEVICE_FUNC
   static unsigned long long (min)() { return 0; }
 };
+template<> struct numeric_limits<bool>
+{
+  EIGEN_DEVICE_FUNC
+  static bool epsilon() { return false; }
+  EIGEN_DEVICE_FUNC
+  static bool (max)() { return true; }
+  EIGEN_DEVICE_FUNC
+  static bool (min)() { return false; }
+};
 
 }