spxout.h

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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*                                                                           */
/*                  This file is part of the class library                   */
/*       SoPlex --- the Sequential object-oriented simPlex.                  */
/*                                                                           */
/*    Copyright (C) 1996-2016 Konrad-Zuse-Zentrum                            */
/*                            fuer Informationstechnik Berlin                */
/*                                                                           */
/*  SoPlex is distributed under the terms of the ZIB Academic Licence.       */
/*                                                                           */
/*  You should have received a copy of the ZIB Academic License              */
/*  along with SoPlex; see the file COPYING. If not email to soplex@zib.de.  */
/*                                                                           */
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/**@file  spxout.h
 * @brief Wrapper for different output streams and verbosity levels.
 */
#ifndef _SPXOUT_H_
#define _SPXOUT_H_

#include <iostream>
#include <iomanip>
#include <assert.h>

#include "spxdefines.h"

// ----------------------------------------------------------------------
//    class SPxOut
// ----------------------------------------------------------------------

namespace soplex 
{

/**@class SPxOut
   @ingroup Elementary

   @brief Wrapper for several output streams. 
   A verbosity level is used to decide which stream to use and whether to
   really print a given message. Regardless of whether the verbosity level
   is set via a manipulator or via the member function, it is persistent
   until a new value is set.

   Most ostream member functions are not provided here; use the corresponding 
   stream manipulators (e.g., @c setprecision()) instead. These are passed on 
   to the <em>current</em> ostream, which is chosen according to the verbosity 
   level. In particular, this means that the first element in an output stream
   should always be the verbosity. For instance, use
   @code
      spxout << verb( SPxOut::WARNING ) << std::setw( 15 ) << 42 << std::endl;
   @endcode
   or 
   @code
      spxout.setVerbosity( SPxOut::WARNING );
      spxout << std::setw( 15 ) << 42 << std::endl;
   @endcode
   instead of
   @code
      spxout << std::setw( 15 ) << verb( SPxOut::WARNING ) << 42 << std::endl;
   @endcode
   in order to make sure that @c std::setw( 15 ) is applied to the warning stream.
*/
class SPxOut
{
public:


   //-----------------------------------
   /**@name Output control types */
   //@{
   /// Verbosity level
   typedef enum 
   {
      // Note: the implementation uses the fact that ERROR == 0 
      // and that the verbosity levels are subsequent numbers.
      // If you change this, change the implementation as well.
      ERROR    = 0, 
      WARNING  = 1,
      DEBUG    = 2,
      INFO1    = 3,
      INFO2    = 4,
      INFO3    = 5
   } Verbosity;

   /// helper struct for the output operator
   struct struct_Verbosity 
   { 
      /// verbosity level
      Verbosity v_; 
   };
   //@}

   //-----------------------------------
   /**@name Construction / destruction */
   //@{
   /// constructor
   SPxOut();
   /// destructor
   virtual ~SPxOut();
   /// copy constructor
   SPxOut( const SPxOut& );
   /// assignment operator
   SPxOut& operator=( const SPxOut& );
   //@}

   //-----------------------------------
   /**@name Verbosity */
   //@{
   ///
   virtual void 
   setVerbosity( const Verbosity& v )
   {
      m_verbosity = v;
   }
   ///
   inline Verbosity
   getVerbosity()
      const
   {
      return m_verbosity;
   }
   //@}

   //----------------------------------------
   /**@name Wrappers for the current stream */
   //@{
   ///
   inline bool good() const
   {
      return getCurrentStream().good();
   }
   ///
   inline bool operator ! () const
   {
      return ! getCurrentStream();
   }
   ///
   inline std::streamsize precision() const
   { 
      return getCurrentStream().precision();
   }
   //@}

   //-----------------------------------
   /**@name Getting / setting streams */
   //@{
   /// Sets the stream for the specified verbosity level.
   virtual void
   setStream( const Verbosity& verbosity,
               std::ostream&   stream )
   {
      m_streams[ verbosity ] = &stream;
   }
   /// Returns the stream for the specified verbosity level.
   inline std::ostream&
   getStream( const Verbosity& verbosity )
      const
   {
      return *(m_streams[ verbosity ]);
   }
   /// Returns the stream for the current verbosity.
   inline std::ostream&
   getCurrentStream()
      const
   {
      return getStream( getVerbosity() );
   }
   //@}

private:

   //-----------------------------------
   /**@name Private data */
   //@{
   /// verbosity level
   Verbosity               m_verbosity;
   /// array of pointers to internal streams, indexed by verbosity level
   std::ostream**          m_streams;
   //@}
};

   // ---------------------------------------------------------
   //    Manipulators
   // ---------------------------------------------------------


   //-------------------------------------------
   /**@name Verbosity manipulator
       Manipulators are implemented in a similar way as done for @c setw(), 
       @c setprecision(), etc. in the standard library file iomanip. For 
       instance, the non-member function \ref verb() "verb(v)" returns a 
       struct struct_Severity which contains only the verbosity level. 
       Calling 
       @code
            SPxOut spxout;
            spxout << verb( SPxOut::ERROR ) << "This is an error!" << std::endl;
       @endcode
       passes such a struct to the output operator defined below, which
       extracts the verbosity level from the struct and passes it to the 
       member function SPxOut::setVerbosity(). 
   */
   //@{
   /// manipulator to be used in an output statement
   inline SPxOut::struct_Verbosity
   verb( const SPxOut::Verbosity&  v )
   {
      SPxOut::struct_Verbosity verbosity;
      verbosity.v_ = v;
      return verbosity;
   }

   /// output operator with verbosity level struct
   inline SPxOut& 
   operator<< ( SPxOut& stream, 
                const SPxOut::struct_Verbosity&  verbosity )
   {
      stream.setVerbosity( verbosity.v_ );
      return stream;
   }
   //@}

   //--------------------------------------------------------
   /**@name Output of standard manipulators and other types
    *
    * We have to define an output operator for many kinds of numeric
    * types here because they can all be more or less casted into each
    * other. When using only a template type, it is not clear what the
    * compiler makes out of it (according to lint).
    */
   //@{
   ///
#define PASS_TO_CURRENT_OSTREAM( t ) \
      _spxout.getCurrentStream() << t; \
      return _spxout;

   /// Passes instances of type \p Type to the current stream. 
#define DEFINE_OUTPUT_OPERATOR( Type ) \
   inline SPxOut& \
   operator<< ( SPxOut& _spxout, Type t ) \
   { PASS_TO_CURRENT_OSTREAM( t ) } 

   DEFINE_OUTPUT_OPERATOR( long )
   DEFINE_OUTPUT_OPERATOR( unsigned long )
   DEFINE_OUTPUT_OPERATOR( bool )
   DEFINE_OUTPUT_OPERATOR( short )
   DEFINE_OUTPUT_OPERATOR( unsigned short )
   DEFINE_OUTPUT_OPERATOR( int )
   DEFINE_OUTPUT_OPERATOR( unsigned int )
   DEFINE_OUTPUT_OPERATOR( double )
   DEFINE_OUTPUT_OPERATOR( float )
   DEFINE_OUTPUT_OPERATOR( long double )
   DEFINE_OUTPUT_OPERATOR( const void* )

   /// Passes standard manipulators without arguments, like @c std::endl
   /// or @c std::ios::right to the current stream.
   inline SPxOut&
   operator<< ( SPxOut&       _spxout, 
                std::ostream& (*manip)( std::ostream& ) )
   { PASS_TO_CURRENT_OSTREAM( manip ) }

   //lint -e{818} (pointer could be made const; this is ok.)
   /// Passes everything else to the current stream. In particular, 
   /// this includes structs corresponding to manipulators with arguments, 
   /// such as the struct @c _Setw for the @c setw() manipulator.
   template< typename T >
   inline SPxOut&
   operator<< ( SPxOut& _spxout, T  t )
   { PASS_TO_CURRENT_OSTREAM( t ) }
   //@}

}  // namespace soplex

#endif // _SPXOUT_H_