[pclasses-devel] Unification of Any and Variant

[Marc D. <bdu...@gm...>]

I just had the idea that one could unify P::Util::Any and P::Util::Variant. 
They do basically both the same, but Any uses typeid and casting, while 
Variant (the class formerly known as LexT) uses stream based conversion.

This would simply require to add a convertTo member function to Any that 
allows stream based conversion additionally to the any_casts:

template <typename ValueType>
ValueType convertTo(const ValueType& defVal = ValueType()) const {			
  Any::holder<ValueType>* valHolder = 0;
  valHolder = dynamic_cast< Any::holder<ValueType>* >(m_data);
  if(valHolder) {
    return valHolder->value();
  }

  ValueType retVal(defVal);
  std::stringstream ss;
  m_data->output(ss);
  ss >> retVal; 
  return retVal;
}


The dynamic_cast is a short cut.

In code you would do this:

Any myAny(5);
string s = myAny.convertTo<std::string>();

or we add a type conversion member to Any that does this automatically:

template <typename T>
operator T() const throw() {
	return this->template convertTo<T>();
}


Does anybody see a problem with this?

Marc