[Question] Custom StringType template parameter (possibility for a KeyType template parameter) #772

I've been using this library quite a bit but am encountering one minor issue when using the dump() routine. I understand that the default std::map<StringType, basic_json> ordering used for iteratiors is lexicographical and that this is the ordering used for output in dump(). This is a direct result of std::less being used for the comparison functor as part of the ObjectType template parameter list.

Ideally, it would be nice to have a KeyType template parameter which complies with the default constructor for StringType but otherwise only needs to implement the operator<() as required for std::map.

Ideally i'd like my "KeyType" just to be as follows:
struct OrderedKey
{
std::string keyName;
unsigned int keyOrder;
};

comparison and "toString" operators would be defined for this custom key as well.

My question: Is it possible that this could be a feature in the foreseeable future? Or am I over thinking this? Essentially i just want to be able to define the order in which my keys are printed in dump() without rewriting the dump command.

Thanks.