JSON parser does not work with "boost::any" as value type

[milacher@…]

I have a property_tree specialization with boost::any as value type, as such:

typedef boost::property_tree::basic_ptree<std::string, boost::any> AnyPTree;

With the help of a set of "translator_between" specializations, and an operator

template <class CharT, class Traits, class Allocator> boost::any& operator += (

boost::any& lhs, const std::basic_string<CharT, Traits, Allocator>& rhs );

I was able to use all the parsers in property_tree in boost 1.58. However the new JSON parser in 1.59 assumes that the value type of the property_tree is string-like and does not compile for my specialization anymore (standard_callbacks is the offending code).