Heterogeneous container

[Chris_F]

I'm faced with a problem.

I'd like to have something along the lines of a heterogeneous map class, eg:

heterogeneous_map map;
map.set<std::string>("name", "Chris");
map.set<int>("age", 23);
std::string name = map.get<std::string>("name");
int age = map.get<int>("age");

This isn't particularly hard to achieve with a std::map<std::string, boost::any>, the problem arises because I need to be able to serialize and de-serialize these heterogeneous maps. I'm using Boost::Serialization, which works very well for most things I've tried so far, but it has no support for serializing a boost::any object. What can I do?

[superbonzo]

AFAIR, variant's are serializable, but you will need to predefine the set of storable types. Do you really need a boost::any like level of heterogeneity ?

[Chris_F]

AFAIR, variant's are serializable, but you will need to predefine the set of storable types. Do you really need a boost::any like level of heterogeneity ?

Actually, I've never used Boost::Variant before, and am not sure how it would be used to make a heterogeneous container.

EDIT: Ok, I just found the function boost::get which makes things a lot easier. This may work for my needs.

[Chris_F]

Actually, that may not be necessary.

There is Boost.PropertyTree that has basically that exact interface, and furthermore, it already works with the serializer!

boost::property_tree::ptree pt;
pt.put<std::string>("name", "Chris");
pt.put("age", 23);
std::ofstream ofs("out.xml");
boost::archive::xml_oarchive xml(ofs);
xml << BOOST_SERIALIZATION_NVP(pt);

[superbonzo]

beware that boost ptree will store everything as strings, using iostream operator, lexical cast and user defined translators to map types to strings and viceversa. So, it's a very different design from <any> or <variant> that store the real objects on the heap and on the stack, respectively ...

[Chris_F]

beware that boost ptree will store everything as strings, using iostream operator, lexical cast and user defined translators to map types to strings and viceversa. So, it's a very different design from <any> or <variant> that store the real objects on the heap and on the stack, respectively ...

Well, I suppose I'll be using it for configuration structures of basic type values which need to be written to/from file. In other words, I think I'm using it for exactly what is was meant for.