/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkVariantCast.h

-------------------------------------------------------------------------
  Copyright 2008 Sandia Corporation.
  Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
  the U.S. Government retains certain rights in this software.
-------------------------------------------------------------------------

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/

/**
 * @class   vtkVariantCast
 *
 * Converts a vtkVariant to some other type.  Wherever possible, implicit conversions are
 * performed, so this method can be used to convert from nearly any type to a string, or
 * from a string to nearly any type.  Note that some conversions may fail at runtime, such
 * as a conversion from the string "abc" to a numeric type.
 *
 * The optional 'valid' flag can be used by callers to verify whether conversion succeeded.
 *
 * @par Thanks:
 * Developed by Timothy M. Shead (tshead@sandia.gov) at Sandia National Laboratories.
*/

#ifndef vtkVariantCast_h
#define vtkVariantCast_h

#include "vtkUnicodeString.h"
#include <typeinfo> // for warnings

template<typename T>
T vtkVariantCast(const vtkVariant& value, bool* valid = nullptr)
{
  vtkGenericWarningMacro(
    << "Cannot convert vtkVariant containing [" << value.GetTypeAsString() << "] "
    << "to unsupported type [" << typeid(T).name() << "].  "
    << "Create a vtkVariantCast<> specialization to eliminate this warning."
    );

  if(valid)
    *valid = false;

  static T dummy;
  return dummy;
}

template<>
inline char vtkVariantCast<char>(const vtkVariant& value, bool* valid)
{
  return value.ToChar(valid);
}

template<>
inline signed char vtkVariantCast<signed char>(const vtkVariant& value, bool* valid)
{
  return value.ToSignedChar(valid);
}

template<>
inline unsigned char vtkVariantCast<unsigned char>(const vtkVariant& value, bool* valid)
{
  return value.ToUnsignedChar(valid);
}

template<>
inline short vtkVariantCast<short>(const vtkVariant& value, bool* valid)
{
  return value.ToShort(valid);
}

template<>
inline unsigned short vtkVariantCast<unsigned short>(const vtkVariant& value, bool* valid)
{
  return value.ToUnsignedShort(valid);
}

template<>
inline int vtkVariantCast<int>(const vtkVariant& value, bool* valid)
{
  return value.ToInt(valid);
}

template<>
inline unsigned int vtkVariantCast<unsigned int>(const vtkVariant& value, bool* valid)
{
  return value.ToUnsignedInt(valid);
}

template<>
inline long vtkVariantCast<long>(const vtkVariant& value, bool* valid)
{
  return value.ToLong(valid);
}

template<>
inline unsigned long vtkVariantCast<unsigned long>(const vtkVariant& value, bool* valid)
{
  return value.ToUnsignedLong(valid);
}

template<>
inline long long vtkVariantCast<long long>(const vtkVariant& value, bool* valid)
{
  return value.ToLongLong(valid);
}

template<>
inline unsigned long long vtkVariantCast<unsigned long long>(const vtkVariant& value, bool* valid)
{
  return value.ToUnsignedLongLong(valid);
}

template<>
inline float vtkVariantCast<float>(const vtkVariant& value, bool* valid)
{
  return value.ToFloat(valid);
}

template<>
inline double vtkVariantCast<double>(const vtkVariant& value, bool* valid)
{
  return value.ToDouble(valid);
}

template<>
inline vtkStdString vtkVariantCast<vtkStdString>(const vtkVariant& value, bool* valid)
{
  if(valid)
    *valid = true;

  return value.ToString();
}

template<>
inline vtkUnicodeString vtkVariantCast<vtkUnicodeString>(const vtkVariant& value, bool* valid)
{
  if(valid)
    *valid = true;

  return value.ToUnicodeString();
}

template<>
inline vtkVariant vtkVariantCast<vtkVariant>(const vtkVariant& value, bool* valid)
{
  if(valid)
    *valid = true;

  return value;
}

#endif

// VTK-HeaderTest-Exclude: vtkVariantCast.h
