Added virtual destructor to reader and writer classes in order to avoid compiler warnings.

git-svn-id: http://www.openmesh.org/svnrepo/OpenMesh/trunk@84 fdac6126-5c0c-442c-9429-916003d36597

Core/IO/reader/BaseReader.hh

@@ -69,6 +69,9 @@ class BaseReader
 {
 public:
 
+  /// Destructor
+  virtual ~BaseReader() {};
+
   /// Returns a brief description of the file type that can be parsed.
   virtual std::string get_description() const = 0;
   

Core/IO/reader/OFFReader.hh

@@ -101,6 +101,9 @@ public:
 
   _OFFReader_();
 
+  /// Destructor
+  virtual ~_OFFReader_() {};
+
   std::string get_description() const { return "Object File Format"; }
   std::string get_extensions()  const { return "off"; }
   std::string get_magic()       const { return "OFF"; }

Core/IO/reader/STLReader.hh

@@ -74,6 +74,9 @@ public:
   // constructor
   _STLReader_();
 
+  /// Destructor
+  virtual ~_STLReader_() {};
+
 
   std::string get_description() const 
   { return "Stereolithography Interface Format"; }