This is neat and C++11 is pretty exciting, but one thing that C++ doesn't need is the further propagation of tuples into non-generic code. Requiring make_tuple instead of allowing shorthand was the right decision.
Tuples in python are a reasonable tradeoff between not wanting to declare anything and the hassle of anonymous structure. This doesn't apply C++ where the equivalent is the POD struct:
//In the olden days we could not initialize a map inline like this
//Key -> metadata mapping. Unfortunately strutcts cannot be declared
//inside a template declaration.
struct TagData { int start; int length; StrToStr mapfun; };
const map<const string, const TagData> TagDataMap {
{"title" , { 3, 30, stripnulls}},
{"artist" , { 33, 30, stripnulls}},
{"album" , { 63, 30, stripnulls}},
{"year" , { 93, 4, stripnulls}},
{"comment" , { 97, 29, stripnulls}},
{"genre" , {127, 1, ord}}};
Creating a named struct pays off when it's time to use the Map, no extra locals or tie() needed to write clear code:
//for loops over collections are finally convenient to use.
for(auto td : TagDataMap){
//C++ created a horrible precedent by making the data type of
//a map pair<K,V> instead of struct ValueType { K key; V value; };
auto tdd = td.second;
ret[td.first] = tdd.mapfun(sbuf.substr(tdd.start, tdd.length));
}
Yes, of course a POD is better, but that would be cheating, since this is supposed to show that you can do the Python stuff, including tuples and tuple deconstruction, just like in the linked Python original.
Tuples in python are a reasonable tradeoff between not wanting to declare anything and the hassle of anonymous structure. This doesn't apply C++ where the equivalent is the POD struct:
Creating a named struct pays off when it's time to use the Map, no extra locals or tie() needed to write clear code: http://liveworkspace.org/code/bcd52515fb7161858e974b7ff3c0aa...