1 files changed, 34 insertions, 0 deletions
diff --git a/src/corelib/tools/qcontainertools_impl.h b/src/corelib/tools/qcontainertools_impl.h
index 3a0c4381f1..1716e0a5a8 100644
--- a/src/corelib/tools/qcontainertools_impl.h
+++ b/src/corelib/tools/qcontainertools_impl.h
@@ -53,6 +53,40 @@ QT_BEGIN_NAMESPACE
 
 namespace QtPrivate
 {
+
+/*!
+  \internal
+
+  Returns whether \a p is within a range [b, e). In simplest form equivalent to:
+  b <= p < e.
+*/
+template<typename T, typename Cmp = std::less<const T *>>
+static constexpr bool q_points_into_range(const T *p, const T *b, const T *e,
+                                          Cmp less = {}) noexcept
+{
+    return !less(p, b) && less(p, e);
+}
+
+/*!
+    \internal
+
+    A wrapper around std::rotate(), with an optimization for
+    Q_RELOCATABLE_TYPEs. We omit the return value, as it would be more work to
+    compute in the Q_RELOCATABLE_TYPE case and, unlike std::rotate on
+    ForwardIterators, callers can compute the result in constant time
+    themselves.
+*/
+template <typename T>
+void q_rotate(T *first, T *mid, T *last)
+{
+    if (QTypeInfo<T>::isRelocatable) {
+        const auto cast = [](T *p) { return reinterpret_cast<uchar*>(p); };
+        std::rotate(cast(first), cast(mid), cast(last));
+    } else {
+        std::rotate(first, mid, last);
+    }
+}
+
 template <typename Iterator>
 using IfIsInputIterator = typename std::enable_if<
     std::is_convertible<typename std::iterator_traits<Iterator>::iterator_category, std::input_iterator_tag>::value,