diff --git a/src/SMESH/SMESH_Comment.hxx b/src/SMESH/SMESH_Comment.hxx
new file mode 100644
index 000000000..9385dab54
--- /dev/null
+++ b/src/SMESH/SMESH_Comment.hxx
@@ -0,0 +1,69 @@
+//  SMESH SMESH : implementaion of SMESH idl descriptions
+//
+//  Copyright (C) 2003  OPEN CASCADE, EADS/CCR, LIP6, CEA/DEN,
+//  CEDRAT, EDF R&D, LEG, PRINCIPIA R&D, BUREAU VERITAS 
+// 
+//  This library is free software; you can redistribute it and/or 
+//  modify it under the terms of the GNU Lesser General Public 
+//  License as published by the Free Software Foundation; either 
+//  version 2.1 of the License. 
+// 
+//  This library is distributed in the hope that it will be useful, 
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of 
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU 
+//  Lesser General Public License for more details. 
+// 
+//  You should have received a copy of the GNU Lesser General Public 
+//  License along with this library; if not, write to the Free Software 
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA 
+// 
+// See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
+//
+//
+// File      : SMESH_Comment.hxx
+// Created   : Wed Mar 14 18:28:45 2007
+// Author    : Edward AGAPOV (eap)
+// Module    : SMESH
+// $Header: 
+
+
+#ifndef SMESH_Comment_HeaderFile
+#define SMESH_Comment_HeaderFile
+
+# include <string>
+# include <sstream>
+
+using namespace std;
+
+/*!
+ * \brief Class to generate string from any type
+ */
+class SMESH_Comment : public string
+{
+  ostringstream _s ;
+
+public :
+
+  SMESH_Comment():string("") {}
+
+  SMESH_Comment(const SMESH_Comment& c):string() {
+    _s << c.c_str() ;
+    this->string::operator=( _s.str() );
+  }
+
+  template <class T>
+  SMESH_Comment( const T &anything ) {
+    _s << anything ;
+    this->string::operator=( _s.str() );
+  }
+
+  template <class T>
+  SMESH_Comment & operator<<( const T &anything ) {
+    _s << anything ;
+    this->string::operator=( _s.str() );
+    return *this ;
+  }
+};
+
+
+#endif
diff --git a/src/SMESH/SMESH_ComputeError.hxx b/src/SMESH/SMESH_ComputeError.hxx
new file mode 100644
index 000000000..91f2712c2
--- /dev/null
+++ b/src/SMESH/SMESH_ComputeError.hxx
@@ -0,0 +1,103 @@
+//  SMESH SMESH : implementaion of SMESH idl descriptions
+//
+//  Copyright (C) 2003  OPEN CASCADE, EADS/CCR, LIP6, CEA/DEN,
+//  CEDRAT, EDF R&D, LEG, PRINCIPIA R&D, BUREAU VERITAS 
+// 
+//  This library is free software; you can redistribute it and/or 
+//  modify it under the terms of the GNU Lesser General Public 
+//  License as published by the Free Software Foundation; either 
+//  version 2.1 of the License. 
+// 
+//  This library is distributed in the hope that it will be useful, 
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of 
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU 
+//  Lesser General Public License for more details. 
+// 
+//  You should have received a copy of the GNU Lesser General Public 
+//  License along with this library; if not, write to the Free Software 
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA 
+// 
+// See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
+//
+//
+//
+//  File   : SMESH_Hypothesis.hxx
+//  Author : Edward AGAPOV (eap)
+//  Module : SMESH
+//  $Header: 
+
+#ifndef SMESH_ComputeError_HeaderFile
+#define SMESH_ComputeError_HeaderFile
+
+#include <string>
+#include <boost/shared_ptr.hpp>
+
+class SMESH_Algo;
+struct SMESH_ComputeError;
+
+typedef boost::shared_ptr<SMESH_ComputeError> SMESH_ComputeErrorPtr;
+
+// =============================================================
+
+enum SMESH_ComputeErrorName
+{
+  // If you modify it, pls update SMESH_ComputeError::CommonName() below.
+  // Positive values are for algo specific errors
+  COMPERR_OK             = -1,
+  COMPERR_BAD_INPUT_MESH = -2,  //!< wrong mesh on lower submesh
+  COMPERR_STD_EXCEPTION  = -3,  //!< some std exception raised
+  COMPERR_OCC_EXCEPTION  = -4,  //!< OCC exception raised
+  COMPERR_SLM_EXCEPTION  = -5,  //!< SALOME exception raised
+  COMPERR_EXCEPTION      = -6,  //!< other exception raised
+  COMPERR_MEMORY_PB      = -7,  //!< std::bad_alloc exception
+  COMPERR_ALGO_FAILED    = -8,  //!< algo failed for some reason
+  COMPERR_BAD_SHAPE      = -9   //!< bad geometry
+};
+
+// =============================================================
+/*!
+ * \brief Contains algorithm and description of occured error
+ */
+// =============================================================
+
+struct SMESH_ComputeError
+{
+  int               myName; //!< SMESH_ComputeErrorName or anything algo specific
+  std::string       myComment;
+  const SMESH_Algo* myAlgo;
+
+  static SMESH_ComputeErrorPtr New( int               error   = COMPERR_OK,
+                                    std::string       comment = "",
+                                    const SMESH_Algo* algo    = 0)
+  { return SMESH_ComputeErrorPtr( new SMESH_ComputeError( error, comment, algo )); }
+
+  SMESH_ComputeError(int               error   = COMPERR_OK,
+                     std::string       comment = "",
+                     const SMESH_Algo* algo    = 0)
+    :myName(error),myComment(comment),myAlgo(algo) {}
+
+  bool IsOK()     { return myName == COMPERR_OK; }
+  bool IsCommon() { return myName < 0; }
+  inline std::string CommonName() const;
+
+};
+
+#define case2char(err) case err: return #err;
+
+std::string SMESH_ComputeError::CommonName() const
+{
+  switch( myName ) {
+  case2char(COMPERR_OK            );
+  case2char(COMPERR_BAD_INPUT_MESH);
+  case2char(COMPERR_STD_EXCEPTION );
+  case2char(COMPERR_OCC_EXCEPTION );
+  case2char(COMPERR_SLM_EXCEPTION );
+  case2char(COMPERR_EXCEPTION     );
+  case2char(COMPERR_MEMORY_PB     );
+  case2char(COMPERR_ALGO_FAILED   );
+  default:;
+  }
+  return "";
+}
+
+#endif