c++ - Reading file line by line WITHOUT using FOR/WHILE loop -

hey guys here's interesting challenge all. i'm given text file , i'm supposed process information line line. processing part trivial long can obtain individual lines. here's challenge:

1. i must without using for/while loops in code. (this include recursions)
2. i allowed use standard c++ library.

currently right best solution this: is there c++ iterator can iterate on file line line? i'm hoping better 1 not involve creating own iterator class or implementing proxy std::string.

p.s. school assignment , challenge here solve problem using combination of std functionalities , algorithms have no clue how go solving it

ifstream input("somefile")  if (!input) { /* handle error */ }  //mydatatype needs implement operator>>  std::vector<mydatatype> res;  std::istream_iterator<mydatatype> first(input); std::istream_iterator<mydatatype> last; std::copy(first,last, std::back_inserter(res));  //etc.. 

your input operator can this:

std::istream& operator>>(std::istream &in,mydatatype & out) {     std::string str;     std::getline(in,str);     //do str without using loops     return in; } 

there lot of loops here (you dont' want use goto, don't you?), hidden behind std::copy , std::getline