reapplied #ifdef to use long long only under C++11

Author: eddelbuettel

ChangeLog

@@ -1,7 +1,11 @@
+2018-02-05  Dirk Eddelbuettel  <edd@debian.org>
+
+	* inst/include/Eigen/src/Core/arch/CUDA/Half.h (Eigen): Condition use
+	of long long and unsigned long on C++11
+
 2018-02-04  Yixuan Qiu  <yixuan.qiu@cos.name>
 
 	[ In RcppEigen 0.3.3.* branch ]
-
 	* inst/include/Eigen: Updated to the upstream 3.3 branch of Eigen
 	based on version 3.3.4
 	* inst/include/unsupported: Idem

inst/include/Eigen/src/Core/arch/CUDA/Half.h

@@ -116,12 +116,14 @@ struct half : public half_impl::half_base {
   EIGEN_DEVICE_FUNC EIGEN_EXPLICIT_CAST(long) const {
     return static_cast<long>(half_impl::half_to_float(*this));
   }
+  #if EIGEN_HAS_CXX11
   EIGEN_DEVICE_FUNC EIGEN_EXPLICIT_CAST(unsigned long) const {
     return static_cast<unsigned long>(half_impl::half_to_float(*this));
   }
   EIGEN_DEVICE_FUNC EIGEN_EXPLICIT_CAST(long long) const {
     return static_cast<long long>(half_impl::half_to_float(*this));
   }
+  #endif
   EIGEN_DEVICE_FUNC EIGEN_EXPLICIT_CAST(unsigned long long) const {
     return static_cast<unsigned long long>(half_to_float(*this));
   }