add missing include and is_double function

src/OpenMesh/Core/IO/OMFormat.cc

@@ -246,6 +246,16 @@ namespace OMFormat {
   }
 
 
+ //-----------------------------------------------------------------------------
+
+
+  template<>
+  bool is_double<double>(const double&)
+  {
+      return true;
+  }
+
+
 } // namespace OMFormat
   // --------------------------------------------------------------------------
 

src/OpenMesh/Core/IO/OMFormat.hh

@@ -350,6 +350,13 @@ namespace OMFormat {
 #endif
   }
 
+  template <typename T> bool is_double(const T&)
+  {
+    return false;
+  }
+
+  template <> bool is_double<double>(const double&);
+
   template <typename T> bool is_integer(const T)
   {
 #if defined(OM_MISSING_HEADER_LIMITS)

src/OpenMesh/Core/IO/exporter/ExporterT.hh

@@ -65,6 +65,7 @@
 #include <OpenMesh/Core/Utils/vector_cast.hh>
 #include <OpenMesh/Core/Utils/color_cast.hh>
 #include <OpenMesh/Core/IO/exporter/BaseExporter.hh>
+#include <OpenMesh/Core/IO/OMFormat.hh>
 
 
 //=== NAMESPACES ==============================================================