[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 b8ee75a8d4d5484eccf95e78da84a9801a47b5e0..3dd679bd9b79ee87a71bf543361b66eb3db9031f 100644 (file)
--- a/include/llvm/ADT/iterator_range.h
+++ b/include/llvm/ADT/iterator_range.h
@@ -19,17 +19,11 @@
 #ifndef LLVM_ADT_ITERATOR_RANGE_H
 #define LLVM_ADT_ITERATOR_RANGE_H
 
-#include <algorithm>
-#include <iterator>
 #include <utility>
+#include <iterator>
 
 namespace llvm {
 
-template <typename Range>
-struct range_traits {
-  typedef typename Range::difference_type difference_type;
-};
-
 /// \brief A range adaptor for a pair of iterators.
 ///
 /// This just wraps two iterators into a range-compatible interface. Nothing
@@ -39,11 +33,12 @@ class iterator_range {
   IteratorT begin_iterator, end_iterator;
 
 public:
-  // FIXME: We should be using iterator_traits to determine the
-  // difference_type, but most of our iterators do not expose anything like it.
-  typedef int difference_type;
-
-  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)) {}
@@ -52,18 +47,21 @@ public:
   IteratorT end() const { return end_iterator; }
 };
 
-/// \brief Determine the distance between the end() and begin() iterators of
-/// a range. Analogous to std::distance().
-template <class Range>
-typename range_traits<Range>::difference_type distance(Range R) {
-  return std::distance(R.begin(), R.end());
+/// \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));
 }
 
-/// \brief Copies members of a range into the output iterator provided.
-/// Analogous to std::copy.
-template <class Range, class OutputIterator>
-OutputIterator copy(Range In, OutputIterator Result) {
-  return std::copy(In.begin(), In.end(), Result);
+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));
 }
 }