etl/function.h

///\file

/******************************************************************************
The MIT License(MIT)

Embedded Template Library.

Copyright(c) 2014 jwellbelove

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of this software and associated documentation files(the "Software"), to deal
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******************************************************************************/

#ifndef __etl_function__
#define __etl_function__

//*****************************************************************************
///\defgroup function function
/// A set of wrapper templates to allow a member or static function to be called
/// without the caller having to know the specific details of the callee.
/// This template class may be used to link interrupt vectors to specific member
/// functions of a handler class.
///\ingroup utilities
//*****************************************************************************

namespace etl
{
  //***************************************************************************
  ///\ingroup function
  /// The base interface template for function template specialisations.
  ///\tparam TParameter The parameter type expected by the function.
  //***************************************************************************
  template <typename TParameter>
  class ifunction
  {
  public:

    typedef TParameter parameter_type; ///< The type of parameter sent to the function.

    //*************************************************************************
    /// The function operator that will be overridden.
    //*************************************************************************
    virtual void operator ()(TParameter) = 0;
  };

  //***************************************************************************
  ///\ingroup function
  /// The base interface template for functions taking <b>void</b> parameters.
  //***************************************************************************
  template <>
  class ifunction<void>
  {
  public:

    //*************************************************************************
    /// The function operator that will be overridden.
    //*************************************************************************
    virtual void operator ()() = 0;
  };

  //***************************************************************************
  ///\ingroup function
  /// A derived function template that takes an object type and parameter type.
  ///\tparam TObject    The object type that contains the member function.
  ///\tparam TParameter The parameter type accepted by the member function.
  //***************************************************************************
  template <typename TObject, typename TParameter>
  class function : public ifunction<TParameter>
  {
  public:

    typedef TObject    object_type;    ///< The type of object.
    typedef TParameter parameter_type; ///< The type of parameter sent to the function.

    //*************************************************************************
    /// Constructor.
    ///\param object    Reference to the object
    ///\param p_function Pointer to the member function
    //*************************************************************************
    function(TObject& object, 
             void(TObject::* p_function)(TParameter))
      : p_object(&object),
        p_function(p_function)
    {
    }

    //*************************************************************************
    /// The function operator that calls the destination function.
    ///\param data The data to pass to the function.
    //*************************************************************************
    void operator ()(TParameter data)
    {
      // Call the object's member function with the data.
      (p_object->*p_function)(data);
    }

  private:

    TObject* p_object;                        ///< Pointer to the object that contains the function.
    void (TObject::* p_function)(TParameter); ///< Pointer to the member function.
  };

  //***************************************************************************
  ///\ingroup function
  /// A derived function template that takes a parameter type.
  ///\tparam TObject The object type that contains the member function.
  //***************************************************************************
  template <typename TObject>
  class function<TObject, void> : public ifunction<void>
  {
  public:

    //*************************************************************************
    /// Constructor.
    ///\param object   Reference to the object
    ///\param p_function Pointer to the member function
    //*************************************************************************
    function(TObject& object, void(TObject::* p_function)(void))
      : p_object(&object),
        p_function(p_function)
    {
    }

    //*************************************************************************
    /// The function operator that calls the destination function.
    //*************************************************************************
    void operator ()()
    {
      // Call the object's member function.
      (p_object->*p_function)();
    }

  private:

    TObject* p_object;              ///< Pointer to the object that contains the function.
    void (TObject::* p_function)(); ///< Pointer to the member function.
  };

  //***************************************************************************
  ///\ingroup function
  /// Specialisation for static or global functions that take a parameter.
  //***************************************************************************
  template <typename TParameter>
  class function<void, TParameter> : public ifunction<TParameter>
  {
  public:

    //*************************************************************************
    /// Constructor.
    ///\param p_function Pointer to the function
    //*************************************************************************
    function(void(*p_function)(TParameter))
      : p_function(p_function)
    {
    }

    //*************************************************************************
    /// The function operator that calls the destination function.
    ///\param data The data to pass to the function.
    //*************************************************************************
    void operator ()(TParameter data)
    {
      // Call the function with the data.
      (*p_function)(data);
    }

  private:

    void (*p_function)(TParameter); ///< Pointer to the function.
  };

  //***************************************************************************
  ///\ingroup function
  /// Specialisation static functions taking void parameter.
  //***************************************************************************
  template <>
  class function<void, void> : public ifunction<void>
  {
  public:

    //*************************************************************************
    /// Constructor.
    ///\param p_function Pointer to the function.
    //*************************************************************************
    function(void(*p_function)(void))
      : p_function(p_function)
    {
    }

    //*************************************************************************
    /// The function operator that calls the destination function.
    //*************************************************************************
    void operator ()()
    {
      // Call the function.
      (*p_function)();
    }

  private:

    void (*p_function)(); ///< Pointer to the function.
  };
}

#endif