+/// Returns the English suffix for an ordinal integer (-st, -nd, -rd, -th).
+static inline StringRef getOrdinalSuffix(unsigned Val) {
+ // It is critically important that we do this perfectly for
+ // user-written sequences with over 100 elements.
+ switch (Val % 100) {
+ case 11:
+ case 12:
+ case 13:
+ return "th";
+ default:
+ switch (Val % 10) {
+ case 1: return "st";
+ case 2: return "nd";
+ case 3: return "rd";
+ default: return "th";
+ }
+ }
+}
+
+template <typename IteratorT>
+inline std::string join_impl(IteratorT Begin, IteratorT End,
+ StringRef Separator, std::input_iterator_tag) {
+ std::string S;
+ if (Begin == End)
+ return S;
+
+ S += (*Begin);
+ while (++Begin != End) {
+ S += Separator;
+ S += (*Begin);
+ }
+ return S;
+}
+
+template <typename IteratorT>
+inline std::string join_impl(IteratorT Begin, IteratorT End,
+ StringRef Separator, std::forward_iterator_tag) {
+ std::string S;
+ if (Begin == End)
+ return S;
+
+ size_t Len = (std::distance(Begin, End) - 1) * Separator.size();
+ for (IteratorT I = Begin; I != End; ++I)
+ Len += (*Begin).size();
+ S.reserve(Len);
+ S += (*Begin);
+ while (++Begin != End) {
+ S += Separator;
+ S += (*Begin);
+ }
+ return S;
+}
+
+/// Joins the strings in the range [Begin, End), adding Separator between
+/// the elements.
+template <typename IteratorT>
+inline std::string join(IteratorT Begin, IteratorT End, StringRef Separator) {
+ typedef typename std::iterator_traits<IteratorT>::iterator_category tag;
+ return join_impl(Begin, End, Separator, tag());
+}
+