Tab completion functional.

git-svn-id: svn://rakshasa.no/libtorrent/trunk/rtorrent@357 e378c898-3ddf-0310-93e7-cc216c733640

rak/algorithm.h

@@ -75,6 +75,48 @@ advance_bidirectional(_InputIter __first, _InputIter __middle1, _InputIter __las
   return std::make_pair(__middle1, __middle2);
 }
 
+struct
+string_starts_with : public std::binary_function<std::string, std::string, bool> {
+  bool operator () (const std::string& complete, const std::string& base) const {
+    return !complete.compare(0, base.size(), base);
+  }
+};
+
+// Count the number of elements from the start of the containers to
+// the first inequal element.
+template <typename _InputIter>
+typename std::iterator_traits<_InputIter>::difference_type
+count_base(_InputIter __first1, _InputIter __last1,
+	   _InputIter __first2, _InputIter __last2) {
+
+  typename std::iterator_traits<_InputIter>::difference_type __n = 0;
+
+  for ( ;__first1 != __last1 && __first2 != __last2; ++__first1, ++__first2, ++__n)
+    if (*__first1 != *__first2)
+      return __n;
+
+  return __n;
+}
+
+template <typename _InputIter>
+typename std::iterator_traits<_InputIter>::value_type
+make_base(_InputIter __first, _InputIter __last) {
+  if (__first == __last)
+    return "";
+
+  typename std::iterator_traits<_InputIter>::value_type __base = *__first++;
+
+  for ( ;__first != __last; ++__first) {
+    typename std::iterator_traits<_InputIter>::difference_type __pos = count_base(__base.begin(), __base.end(),
+										  __first->begin(), __first->end());
+
+    if (__pos < __base.size())
+      __base.resize(__pos);
+  }
+
+  return __base;
+}
+
 }
 
 #endif