X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FADT%2Fiterator_range.h;h=3dd679bd9b79ee87a71bf543361b66eb3db9031f;hb=20c9ab5fe6a097a4f8f7da745dffa39d830d4d6e;hp=6248be90075225dbf0402ef3df1f9b63f77152e7;hpb=26abef7b5a3f239204a1ad605a88b99a1ef878c3;p=oota-llvm.git

diff --git a/include/llvm/ADT/iterator_range.h b/include/llvm/ADT/iterator_range.h
index 6248be90075..3dd679bd9b7 100644
--- a/include/llvm/ADT/iterator_range.h
+++ b/include/llvm/ADT/iterator_range.h
@@ -20,6 +20,7 @@
 #define LLVM_ADT_ITERATOR_RANGE_H
 
 #include <utility>
+#include <iterator>
 
 namespace llvm {
 
@@ -32,7 +33,12 @@ class iterator_range {
   IteratorT begin_iterator, end_iterator;
 
 public:
-  iterator_range() {}
+  //TODO: Add SFINAE to test that the Container's iterators match the range's
+  //      iterators.
+  template <typename Container>
+  iterator_range(Container &&c)
+  //TODO: Consider ADL/non-member begin/end calls.
+      : begin_iterator(c.begin()), end_iterator(c.end()) {}
   iterator_range(IteratorT begin_iterator, IteratorT end_iterator)
       : begin_iterator(std::move(begin_iterator)),
         end_iterator(std::move(end_iterator)) {}
@@ -41,6 +47,22 @@ public:
   IteratorT end() const { return end_iterator; }
 };
 
+/// \brief Convenience function for iterating over sub-ranges.
+///
+/// This provides a bit of syntactic sugar to make using sub-ranges
+/// in for loops a bit easier. Analogous to std::make_pair().
+template <class T> iterator_range<T> make_range(T x, T y) {
+  return iterator_range<T>(std::move(x), std::move(y));
+}
+
+template <typename T> iterator_range<T> make_range(std::pair<T, T> p) {
+  return iterator_range<T>(std::move(p.first), std::move(p.second));
+}
+
+template<typename T>
+iterator_range<decltype(begin(std::declval<T>()))> drop_begin(T &&t, int n) {
+  return make_range(std::next(begin(t), n), end(t));
+}
 }
 
 #endif