usAny.h

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

  Library: CppMicroServices


Copyright Kevlin Henney, 2000, 2001, 2002. All rights reserved.
Extracted from Boost 1.46.1 and adapted for CppMicroServices.

Permission is hereby granted, free of charge, to any person or organization
obtaining a copy of the software and accompanying documentation covered by
this license (the "Software") to use, reproduce, display, distribute,
execute, and transmit the Software, and to prepare derivative works of the
Software, and to permit third-parties to whom the Software is furnished to
do so, all subject to the following:

The copyright notices in the Software and this entire statement, including
the above license grant, this restriction and the following disclaimer,
must be included in all copies of the Software, in whole or in part, and
all derivative works of the Software, unless such copies or derivative
works are solely in the form of machine-executable object code generated by
a source language processor.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.

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

#ifndef US_ANY_H
#define US_ANY_H

#include <algorithm>
#include <typeinfo>
#include <sstream>
#include <vector>
#include <list>
#include <set>
#include <map>

#include <usCoreConfig.h>

US_BEGIN_NAMESPACE

class Any;

US_Core_EXPORT std::string any_value_to_string(const Any& any);

US_Core_EXPORT std::string any_value_to_json(const Any& val);
US_Core_EXPORT std::string any_value_to_json(const std::string& val);
US_Core_EXPORT std::string any_value_to_json(bool val);

template<class T>
std::string any_value_to_string(const T& val)
{
  std::stringstream ss;
  ss << val;
  return ss.str();
}

template<class T>
std::string any_value_to_json(const T& val)
{
  return any_value_to_string(val);
}

template<typename Iterator>
std::string container_to_string(Iterator i1, Iterator i2)
{
  std::stringstream ss;
  ss << "[";
  const Iterator begin = i1;
  for ( ; i1 != i2; ++i1)
  {
    if (i1 == begin) ss << any_value_to_string(*i1);
    else ss << "," << any_value_to_string(*i1);
  }
  ss << "]";
  return ss.str();
}

template<typename Iterator>
std::string container_to_json(Iterator i1, Iterator i2)
{
  std::stringstream ss;
  ss << "[";
  const Iterator begin = i1;
  for ( ; i1 != i2; ++i1)
  {
    if (i1 == begin) ss << any_value_to_json(*i1);
    else ss << "," << any_value_to_json(*i1);
  }
  ss << "]";
  return ss.str();
}

template<class E>
std::string any_value_to_string(const std::vector<E>& vec)
{
  return container_to_string(vec.begin(), vec.end());
}

template<class E>
std::string any_value_to_json(const std::vector<E>& vec)
{
  return container_to_json(vec.begin(), vec.end());
}

template<class E>
std::string any_value_to_string(const std::list<E>& l)
{
  return container_to_string(l.begin(), l.end());
}

template<class E>
std::string any_value_to_json(const std::list<E>& l)
{
  return container_to_json(l.begin(), l.end());
}

template<class E>
std::string any_value_to_string(const std::set<E>& s)
{
  return container_to_string(s.begin(), s.end());
}

template<class E>
std::string any_value_to_json(const std::set<E>& s)
{
  return container_to_json(s.begin(), s.end());
}

template<class M>
std::string any_value_to_string(const std::map<M, Any>& m);

template<class K, class V>
std::string any_value_to_string(const std::map<K, V>& m);

template<class M>
std::string any_value_to_json(const std::map<M, Any>& m);

template<class K, class V>
std::string any_value_to_json(const std::map<K, V>& m);


class Any
{
public:

  Any(): _content(0)
  { }

  template <typename ValueType>
  Any(const ValueType& value)
    : _content(new Holder<ValueType>(value))
  { }

  Any(const Any& other)
    : _content(other._content ? other._content->Clone() : 0)
  { }

  ~Any()
  {
    delete _content;
  }

  Any& Swap(Any& rhs)
  {
    std::swap(_content, rhs._content);
    return *this;
  }

  template <typename ValueType>
  Any& operator = (const ValueType& rhs)
  {
    Any(rhs).Swap(*this);
    return *this;
  }

  Any& operator = (const Any& rhs)
  {
    Any(rhs).Swap(*this);
    return *this;
  }

  bool Empty() const
  {
    return !_content;
  }

  std::string ToString() const
  {
    return _content->ToString();
  }

  std::string ToJSON() const
  {
    return Empty() ? "null" : _content->ToJSON();
  }

  const std::type_info& Type() const
  {
    return _content ? _content->Type() : typeid(void);
  }

private:

  class Placeholder
  {
  public:
    virtual ~Placeholder()
    { }

    virtual std::string ToString() const = 0;
    virtual std::string ToJSON() const = 0;

    virtual const std::type_info& Type() const = 0;
    virtual Placeholder* Clone() const = 0;
  };

  template <typename ValueType>
  class Holder: public Placeholder
  {
  public:
    Holder(const ValueType& value)
      : _held(value)
    { }

    virtual std::string ToString() const override
    {
      return any_value_to_string(_held);
    }

    virtual std::string ToJSON() const override
    {
      return any_value_to_json(_held);
    }

    virtual const std::type_info& Type() const override
    {
      return typeid(ValueType);
    }

    virtual Placeholder* Clone() const override
    {
      return new Holder(_held);
    }

    ValueType _held;

  private: // intentionally left unimplemented
    Holder& operator=(const Holder &);
  };

private:
    template <typename ValueType>
    friend ValueType* any_cast(Any*);

    template <typename ValueType>
    friend ValueType* unsafe_any_cast(Any*);

    Placeholder* _content;
};

class BadAnyCastException : public std::bad_cast
{
public:

  BadAnyCastException(const std::string& msg = "")
    : std::bad_cast(), _msg(msg)
  {}

  ~BadAnyCastException() throw() {}

  virtual const char * what() const throw() override
  {
    if (_msg.empty())
      return "US_PREPEND_NAMESPACE(BadAnyCastException): "
             "failed conversion using US_PREPEND_NAMESPACE(any_cast)";
    else
      return _msg.c_str();
  }

private:

  std::string _msg;
};

template <typename ValueType>
ValueType* any_cast(Any* operand)
{
  return operand && operand->Type() == typeid(ValueType)
      ? &static_cast<Any::Holder<ValueType>*>(operand->_content)->_held
      : 0;
}

template <typename ValueType>
const ValueType* any_cast(const Any* operand)
{
  return any_cast<ValueType>(const_cast<Any*>(operand));
}

template <typename ValueType>
ValueType any_cast(const Any& operand)
{
  ValueType* result = any_cast<ValueType>(const_cast<Any*>(&operand));
  if (!result) throw BadAnyCastException("Failed to convert between const Any types");
  return *result;
}

template <typename ValueType>
ValueType any_cast(Any& operand)
{
  ValueType* result = any_cast<ValueType>(&operand);
  if (!result) throw BadAnyCastException("Failed to convert between Any types");
  return *result;
}

template <typename ValueType>
const ValueType& ref_any_cast(const Any & operand)
{
  ValueType* result = any_cast<ValueType>(const_cast<Any*>(&operand));
  if (!result) throw BadAnyCastException("RefAnyCast: Failed to convert between const Any types");
  return *result;
}

template <typename ValueType>
ValueType& ref_any_cast(Any& operand)
{
  ValueType* result = any_cast<ValueType>(&operand);
  if (!result) throw BadAnyCastException("RefAnyCast: Failed to convert between Any types");
  return *result;
}

template <typename ValueType>
ValueType* unsafe_any_cast(Any* operand)
{
  return &static_cast<Any::Holder<ValueType>*>(operand->_content)->_held;
}

template <typename ValueType>
const ValueType* unsafe_any_cast(const Any* operand)
{
  return any_cast<ValueType>(const_cast<Any*>(operand));
}


template<class K>
std::string any_value_to_string(const std::map<K, Any>& m)
{
  std::stringstream ss;
  ss << "{";
  typedef typename std::map<K, Any>::const_iterator Iterator;
  Iterator i1 = m.begin();
  const Iterator begin = i1;
  const Iterator end = m.end();
  for ( ; i1 != end; ++i1)
  {
    if (i1 == begin) ss << i1->first << " : " << i1->second.ToString();
    else ss << ", " << i1->first << " : " << i1->second.ToString();
  }
  ss << "}";
  return ss.str();
}

template<class K, class V>
std::string any_value_to_string(const std::map<K, V>& m)
{
  std::stringstream ss;
  ss << "{";
  typedef typename std::map<K, V>::const_iterator Iterator;
  Iterator i1 = m.begin();
  const Iterator begin = i1;
  const Iterator end = m.end();
  for ( ; i1 != end; ++i1)
  {
    if (i1 == begin) ss << i1->first << " : " << i1->second;
    else ss << ", " << i1->first << " : " << i1->second;
  }
  ss << "}";
  return ss.str();
}

template<class K>
std::string any_value_to_json(const std::map<K, Any>& m)
{
  std::stringstream ss;
  ss << "{";
  typedef typename std::map<K, Any>::const_iterator Iterator;
  Iterator i1 = m.begin();
  const Iterator begin = i1;
  const Iterator end = m.end();
  for ( ; i1 != end; ++i1)
  {
    if (i1 == begin) ss << "\"" << i1->first << "\" : " << i1->second.ToJSON();
    else ss << ", " << "\"" << i1->first << "\" : " << i1->second.ToJSON();
  }
  ss << "}";
  return ss.str();
}

template<class K, class V>
std::string any_value_to_json(const std::map<K, V>& m)
{
  std::stringstream ss;
  ss << "{";
  typedef typename std::map<K, V>::const_iterator Iterator;
  Iterator i1 = m.begin();
  const Iterator begin = i1;
  const Iterator end = m.end();
  for ( ; i1 != end; ++i1)
  {
    if (i1 == begin) ss << "\"" << i1->first << "\" : " << i1->second;
    else ss << ", " << "\"" << i1->first << "\" : " << i1->second;
  }
  ss << "}";
  return ss.str();
}

US_END_NAMESPACE

#endif // US_ANY_H