Fix obscure MSVC error

common/include/pcl/point_traits.h

@@ -53,6 +53,12 @@
 #include <boost/mpl/bool.hpp>
 #endif
 
+// This is required for the workaround at line 109
+#ifdef _MSC_VER
+#include <Eigen/Core>
+#include <Eigen/src/StlSupport/details.h>
+#endif
+
 namespace pcl
 {
 
@@ -100,6 +106,24 @@ namespace pcl
       typedef PointT type;
     };
 
+#ifdef _MSC_VER
+
+    /* Sometimes when calling functions like `copyPoint()` or `copyPointCloud`
+     * without explicitly specifying point types, MSVC deduces them to be e.g.
+     * `Eigen::internal::workaround_msvc_stl_support<pcl::PointXYZ>` instead of
+     * plain `pcl::PointXYZ`. Subsequently these types are passed to meta-
+     * functions like `has_field` or `fieldList` and make them choke. This hack
+     * makes use of the fact that internally `fieldList` always applies `POD` to
+     * its argument type. This specialization therefore allows to unwrap the
+     * contained point type. */
+    template<typename PointT>
+    struct POD<Eigen::internal::workaround_msvc_stl_support<PointT> >
+    {
+      typedef PointT type;
+    };
+
+#endif
+
     // name
     /* This really only depends on Tag, but we go through some gymnastics to avoid ODR violations.
        We template it on the point type PointT to avoid ODR violations when registering multiple