Generated 'item' type is always std::pair for map containers

[John Pursey]

The generated code for any "map" like container always uses a std::pair. We have an alternate STL implementation in its own namespace and so std::pair<> is incompatible for our map class. In any case, it is more portable to use the map<K,V>::value_type instead as it will always map to the correct type. The current code and proposed change are below:

-------------- CURRENT ---------------
            std::pair<%(KEY_CTYPE)s, %(ITEM_CTYPE)s> item;
            if (!%(KEY_CONVERTER)s(PyTuple_GET_ITEM(tup, 0), &item.first)) {
                return 0;
            }
            if (!%(ITEM_CONVERTER)s(PyTuple_GET_ITEM(tup, 1), &item.second)) {
                return 0;
            }

-------------- PROPOSED ---------------
            %(KEY_CTYPE)s key;
            %(ITEM_CTYPE)s value;
            if (!%(KEY_CONVERTER)s(PyTuple_GET_ITEM(tup, 0), &key)) {
                return 0;
            }
            if (!%(ITEM_CONVERTER)s(PyTuple_GET_ITEM(tup, 1), &value)) {
                return 0;
            }
            %(CTYPE)s::value_type item(key,value);

[Gustavo Carneiro (gjc)]

I would rather avoid the key and value temp vars, if possible, for the sake of efficiency. Question, can we assume %(CTYPE)s::value_type always has a 'first' and 'second', like std::pair, at least?