diff --git a/memory/buffer/circular.cpp b/memory/buffer/circular.cpp
index 822c4afb..3642f619 100644
--- a/memory/buffer/circular.cpp
+++ b/memory/buffer/circular.cpp
@@ -152,6 +152,35 @@ circular<ValueT>::size (void) const
 }
 
 
+//-----------------------------------------------------------------------------
+template <typename ValueT>
+typename circular<ValueT>::iterator
+circular<ValueT>::constrain (iterator cursor)
+{
+    CHECK_LIMIT (cursor, m_begin, m_begin + 2 * size ());
+
+    return m_begin + (cursor - m_begin) % size ();
+}
+
+
+//-----------------------------------------------------------------------------
+template <typename ValueT>
+util::view<typename circular<ValueT>::iterator>
+circular<ValueT>::constrain (util::view<iterator> window)
+{
+    CHECK_LIMIT (window.begin (), m_begin, m_begin + 2 * size ());
+    CHECK_LIMIT (window.end   (), m_begin, m_begin + 2 * size ());
+
+    auto first = window.begin ();
+    auto last  = first + window.size ();
+    util::view res { first, last };
+
+    CHECK_EQ (res.size (), window.size ());
+    CHECK_LE (res.begin (), res.end ());
+    return res;
+}
+
+
 ///////////////////////////////////////////////////////////////////////////////
 template class util::memory::buffer::circular<char>;
 template class util::memory::buffer::circular<uint8_t>;
diff --git a/memory/buffer/circular.hpp b/memory/buffer/circular.hpp
index 36dcf6af..f37785ab 100644
--- a/memory/buffer/circular.hpp
+++ b/memory/buffer/circular.hpp
@@ -17,6 +17,8 @@
 #ifndef __UTIL_MEMORY_BUFFER_CIRCULAR_HPP
 #define __UTIL_MEMORY_BUFFER_CIRCULAR_HPP
 
+#include "../../view.hpp"
+
 #include <cstddef>
 
 namespace util::memory::buffer {
@@ -49,6 +51,13 @@ namespace util::memory::buffer {
 
         size_t size (void) const;
 
+        /// rebases the pointer so that it points to within the first
+        /// repetition of the data buffer.
+        iterator constrain (iterator);
+        /// rebases a pair of pointers so they fall within a contiguous span of
+        /// the data buffer.
+        util::view<iterator> constrain (util::view<iterator>);
+
     private:
         value_type *m_begin, *m_end;