Uso de Doxygen para generar documentación en inglés y en español

#ifdef English_dox
/// Defined by the C++ standard library.
#endif
#ifdef Spanish_dox
/// Definido por la biblioteca estándar C++.
#endif
namespace std { } // trick to include it into the Doxygen documentation

// CSV.h    (C) 2008 adolfo@di-mare.com
// ...

#ifdef English_dox
/** Deletes \c ch when it is the trailing character in \c str.
    - The deleted character always is \c ch.

    \dontinclude test_CSV.cpp
    \skipline    test::chop()
    \until       }}
    \see         test_CSV::test_chop()
*/
#endif
void chop( std::string & str , char ch=0 );

// ...
// EOF: CSV.h

// CSV.es.h  (C) 2008 adolfo@di-mare.com

#ifdef Spanish_dox
    /// Documentación en español.
    #define Spanish_dox "Documentación en español"
   /// \def Spanish_dox  ///< Marca bloques de documentación en español.
#endif
// ...

/** \fn    void chop( std::string & str , char ch=0 );
    \brief Elimina \c ch si es el último caracter de \c str.
    - El caracter eliminado siempre es \c ch.

    \dontinclude test_CSV.cpp
    \skipline    test::chop()
    \until       }}
    \see         test_CSV::test_chop()
*/

// ...
// EOF: CSV.es.h

Comparing files test_CSV.dxg and Spanish.dxg
***** test_CSV.dxg
PROJECT_NAME          = "CSV:"
OUTPUT_LANGUAGE       = English
OUTPUT_DIRECTORY      = .
***** Spanish.dxg
PROJECT_NAME          = "CSV:"
OUTPUT_LANGUAGE       = Spanish
OUTPUT_DIRECTORY      = .
*****

***** test_CSV.dxg
INPUT                 = CSV.cpp      CSV_line.cpp test_CSV.cpp \
                        CSV.h        CSV_line.h
RECURSIVE             = NO
***** Spanish.dxg
INPUT                 = CSV.cpp      CSV_line.cpp test_CSV.cpp \
                        CSV.h        CSV_line.h                \
                        Spanish.txt
#                       copy CSV_line.es.h+CSV.es.h Spanish.txt
RECURSIVE             = NO
*****

***** test_CSV.dxg
PREDEFINED            = "DOXYGEN_COMMENT" \
                        "English_dox" \
                        "__cplusplus" \
***** Spanish.dxg
PREDEFINED            = "DOXYGEN_COMMENT" \
                        "Spanish_dox" \
                        "__cplusplus" \
*****

// #1
#ifdef English_dox
#endif
#ifdef Spanish_dox
#endif

// #2
#ifdef English_dox
/**
    \fn    iterJava::hasNext() const;
    \brief Returns \c true if the iteration has more elements.
           (In other words, returns \c true if \c next() would
           return an element rather than breaking up.)
    \returns \c true if the iterator has more elements.
*/
#endif
#ifdef Spanish_dox
#endif
/**
    \dontinclude test_iterJava.cpp
    \skipline    test::next()
    \until       }}
    \see         test_iterJava::test_next()
*/

// #3
#ifdef English_dox
/**
    \fn    iterJava::hasNext() const;
    \brief Returns \c true if the iteration has more elements.
           (In other words, returns \c true if \c next() would
           return an element rather than breaking up.)
    \returns \c true if the iterator has more elements.
*/
#endif
#ifdef Spanish_dox
    \fn    iterJava::hasNext() const;
    \brief Retorna \c true si la iteración tiene más elementos.
           (En otras palabras, retorna \c true si \c next()
           retornaría un elemento en lugar de fallar.)
    \returns \c true si la iteración tiene más elementos.
#endif
/**
    \dontinclude test_iterJava.cpp
    \skipline    test::next()
    \until       }}
    \see         test_iterJava::test_next()
*/

// CSV.h    (C) 2008 adolfo@di-mare.com

#ifdef English_dox
    /// Doxygen English documentation.
    #define English_dox   "Doxygen English documentation"
   /// \def English_dox  ///< Macro used to have Doxygen generate English documentation.
#endif
#ifdef Spanish_dox
    /// Documentación en español.
    #define Spanish_dox "Documentación en español"
   /// \def Spanish_dox  ///< Macro usado para que Doxygen genere documentación en español.
#endif

// ...

// EOF: CSV.h

#ifdef English_dox
/// Uses \c getNextCSV() to scan and store complete CSV lines.
/// - Oftentimes it helps a lot to \c chop() out trailing CR+LF's.
/// - This class is derived from std::vector<std::string> and has
///   all vector operations and interfaces.
#endif
class CSV_line : public std::vector<std::string> {
public:
    CSV_line();
    CSV_line( const std::string & str );
    CSV_line( const char *pz_str , size_t n=0 );
    CSV_line( const CSV_line & );
    void setData( const std::string & str );
    void setData( const char *pz_str , size_t n=0 );
    friend class test_CSV;
};

#ifdef English_dox
/// \class   test_CSV;
/// \brief   Tests cases for \c CSV_line.
#endif

#ifdef English_dox
/// Constructor.
#endif
inline CSV_line::CSV_line() { }

class CSV_line : public std::vector<std::string> {
public:
    #ifdef English_dox
    /// Constructor.
    #endif
    CSV_line();
    CSV_line( const std::string & str );
    CSV_line( const char *pz_str , size_t n=0 );
    CSV_line( const CSV_line & );
    void setData( const std::string & str );
    void setData( const char *pz_str , size_t n=0 );
    #ifdef English_dox
    /// Tests cases for \c CSV_line.
    #endif
    friend class test_CSV;
};