Add a family of "has field" meta-functions

common/include/pcl/point_types.h

@@ -42,6 +42,9 @@
 #include <pcl/pcl_macros.h>
 #include <bitset>
 #include <pcl/register_point_struct.h>
+#include <boost/mpl/contains.hpp>
+#include <boost/mpl/fold.hpp>
+#include <boost/mpl/vector.hpp>
 
 /**
   * \file pcl/point_types.h
@@ -666,6 +669,79 @@ namespace pcl
       }
     }
   };
+
+  namespace traits
+  {
+
+    /** \brief Metafunction to check if a given point type has a given field.
+     *
+     *  Example usage at run-time:
+     *
+     *  \code
+     *  bool curvature_available = pcl::traits::has_field<PointT, pcl::fields::curvature>::value;
+     *  \endcode
+     *
+     *  Example usage at compile-time:
+     *
+     *  \code
+     *  BOOST_MPL_ASSERT_MSG ((pcl::traits::has_field<PointT, pcl::fields::label>::value),
+     *                        POINT_TYPE_SHOULD_HAVE_LABEL_FIELD,
+     *                        (PointT));
+     *  \endcode
+     */
+    template <typename PointT, typename Field>
+    struct has_field : boost::mpl::contains<typename pcl::traits::fieldList<PointT>::type, Field>::type
+    { };
+
+    /** Metafunction to check if a given point type has all given fields. */
+    template <typename PointT, typename Field>
+    struct has_all_fields : boost::mpl::fold<Field,
+                                             boost::mpl::bool_<true>,
+                                             boost::mpl::and_<boost::mpl::_1,
+                                                              has_field<PointT, boost::mpl::_2> > >::type
+    { };
+
+    /** Metafunction to check if a given point type has any of the given fields. */
+    template <typename PointT, typename Field>
+    struct has_any_field : boost::mpl::fold<Field,
+                                            boost::mpl::bool_<false>,
+                                            boost::mpl::or_<boost::mpl::_1,
+                                                            has_field<PointT, boost::mpl::_2> > >::type
+    { };
+
+    /** Metafunction to check if a given point type has x, y, and z fields. */
+    template <typename PointT>
+    struct has_xyz : has_all_fields<PointT, boost::mpl::vector<pcl::fields::x,
+                                                               pcl::fields::y,
+                                                               pcl::fields::z> >
+    { };
+
+    /** Metafunction to check if a given point type has normal_x, normal_y, and
+      * normal_z fields. */
+    template <typename PointT>
+    struct has_normal : has_all_fields<PointT, boost::mpl::vector<pcl::fields::normal_x,
+                                                                  pcl::fields::normal_y,
+                                                                  pcl::fields::normal_z> >
+    { };
+
+    /** Metafunction to check if a given point type has curvature field. */
+    template <typename PointT>
+    struct has_curvature : has_field<PointT, pcl::fields::curvature>
+    { };
+
+    /** Metafunction to check if a given point type has either rgb or rgba field. */
+    template <typename PointT>
+    struct has_color : has_any_field<PointT, boost::mpl::vector<pcl::fields::rgb,
+                                                                pcl::fields::rgba> >
+    { };
+
+    /** Metafunction to check if a given point type has label field. */
+    template <typename PointT>
+    struct has_label : has_field<PointT, pcl::fields::label>
+    { };
+
+  }
+
 } // namespace pcl
 
 #if defined _MSC_VER

test/common/test_common.cpp

@@ -1140,6 +1140,37 @@ TEST (PCL, IsSamePointType)
   EXPECT_FALSE (status);
 }
 
+//////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+TEST (PCL, HasField)
+{
+  // has_field
+  EXPECT_TRUE ((pcl::traits::has_field<pcl::Normal, pcl::fields::curvature>::value));
+  EXPECT_FALSE ((pcl::traits::has_field<pcl::PointXYZ, pcl::fields::curvature>::value));
+  // has_all_fields
+  EXPECT_TRUE ((pcl::traits::has_all_fields<pcl::PointXYZRGB, boost::mpl::vector<pcl::fields::x, pcl::fields::rgb> >::value));
+  EXPECT_FALSE ((pcl::traits::has_all_fields<pcl::PointXYZ, boost::mpl::vector<pcl::fields::x, pcl::fields::rgb> >::value));
+  // has_any_field
+  EXPECT_TRUE ((pcl::traits::has_any_field<pcl::PointXYZ, boost::mpl::vector<pcl::fields::x, pcl::fields::normal_x> >::value));
+  EXPECT_TRUE ((pcl::traits::has_any_field<pcl::Normal, boost::mpl::vector<pcl::fields::x, pcl::fields::normal_x> >::value));
+  EXPECT_FALSE ((pcl::traits::has_any_field<pcl::RGB, boost::mpl::vector<pcl::fields::x, pcl::fields::normal_x> >::value));
+  // has_xyz
+  EXPECT_TRUE ((pcl::traits::has_xyz<pcl::PointXYZ>::value));
+  EXPECT_FALSE ((pcl::traits::has_xyz<pcl::Normal>::value));
+  // has_normal
+  EXPECT_TRUE ((pcl::traits::has_normal<pcl::PointNormal>::value));
+  EXPECT_FALSE ((pcl::traits::has_normal<pcl::PointXYZ>::value));
+  // has_curvature
+  EXPECT_TRUE ((pcl::traits::has_curvature<pcl::PointNormal>::value));
+  EXPECT_FALSE ((pcl::traits::has_curvature<pcl::RGB>::value));
+  // has_color
+  EXPECT_TRUE ((pcl::traits::has_color<pcl::PointXYZRGB>::value));
+  EXPECT_TRUE ((pcl::traits::has_color<pcl::PointXYZRGBA>::value));
+  EXPECT_FALSE ((pcl::traits::has_color<pcl::PointXYZ>::value));
+  // has_label
+  EXPECT_TRUE ((pcl::traits::has_label<pcl::PointXYZL>::value));
+  EXPECT_FALSE ((pcl::traits::has_label<pcl::Normal>::value));
+}
+
 /* ---[ */
 int
 main (int argc, char** argv)