À la STL find_range()

I started by writing some code for the typical interviewee question and ended up factoring out part of it in a function I called find_range:

template <typename BidirectionalIterator_t, typename Predicate_t>

pair<BidirectionalIterator_t, BidirectionalIterator_t> find_range(BidirectionalIterator_t first, 
                                                                  BidirectionalIterator_t last,

                                                                  Predicate_t             predicate) {

   first = find_if(first, last, predicate);

   pair<BidirectionalIterator_t, BidirectionalIterator_t> result(first,first);

   if (result.first != last) {


      result.second = find_if_not(result.second, last, predicate);


   return result;



With it, writing a ReverseWords function becomes much more elegant:

void ReverseWords(wstring & s) { 
   pair<wstring::iterator, wstring::iterator> word;

   word.first = s.begin();

   while (word.first != s.end()) {

      word = find_range(word.first, s.end(), [] (wchar_t ch) {return !iswspace(ch);});

      reverse(word.first, word.second);

      word.first = word.second;




Joyeux Noël!



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