[ADT] Apply a large hammer to StringRef functions: attribute always_inline.

[oota-llvm.git] / include / llvm / ADT / iterator_range.h

diff --git a/include/llvm/ADT/iterator_range.h b/include/llvm/ADT/iterator_range.h
index 4f2f3218f3104cfc4369e3db368fdfe0148f306f..3dd679bd9b79ee87a71bf543361b66eb3db9031f 100644 (file)
--- 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)) {}
@@ -40,6 +46,23 @@ public:
   IteratorT begin() const { return begin_iterator; }
   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