Question

I dont understand what does that piece of code does

static TwoWayHostPair hostpair;
map <TwoWayHostPair, Traffic> mymap;
//here some map element inserted to mymap and hostpair initialized

map <TwoWayHostPair, Traffic>::iterator iter = mymap.begin();
iter = mymap.find(hostpair);
if (iter == mymap.end()) { 
    iter = mymap.insert(make_pair(hostPair, Traffic())).first; //line8
}

My question is what happens in line8? I didnt get it. Isnt it supposed to be type map<...>:iterator and after this insertion does it stay same type?

Answer 1

std::map::insert return std::pair< iterator,bool >, below statement is correct. second bool return value indicates whether the insertion took place

iter = mymap.insert(make_pair(hostPair, Traffic())).first; //line8

see reference here