diff --git a/io_posix.cpp b/io_posix.cpp
index 5e7bd692..a3846da3 100644
--- a/io_posix.cpp
+++ b/io_posix.cpp
@@ -79,7 +79,8 @@ mapped_file::empty (void) const
 
 //////////////////////////////////////////////////////////////////////////////
 uint8_t*
-mapped_file::data (void) {
+mapped_file::data (void) &
+{
     CHECK (m_size > 0);
     CHECK (m_data != NULL);
 
@@ -89,7 +90,8 @@ mapped_file::data (void) {
 
 //----------------------------------------------------------------------------
 const uint8_t*
-mapped_file::data (void) const {
+mapped_file::data (void) const &
+{
     CHECK (m_size > 0);
     CHECK (m_data != NULL);
 
@@ -99,21 +101,23 @@ mapped_file::data (void) const {
 
 //----------------------------------------------------------------------------
 uint8_t*
-mapped_file::begin (void) {
+mapped_file::begin (void) &
+{
     return data ();
 }
 
 
 //----------------------------------------------------------------------------
 uint8_t*
-mapped_file::end (void) {
+mapped_file::end (void) &
+{
     return data () + size ();
 }
 
 
 //-----------------------------------------------------------------------------
 const uint8_t*
-mapped_file::begin (void) const
+mapped_file::begin (void) const &
 {
     return data ();
 }
@@ -121,7 +125,7 @@ mapped_file::begin (void) const
 
 //-----------------------------------------------------------------------------
 const uint8_t*
-mapped_file::end (void) const
+mapped_file::end (void) const &
 {
     return data () + size ();
 }
@@ -129,14 +133,16 @@ mapped_file::end (void) const
 
 //----------------------------------------------------------------------------
 const uint8_t*
-mapped_file::cbegin (void) const {
+mapped_file::cbegin (void) const &
+{
     return data ();
 }
 
 
 //----------------------------------------------------------------------------
 const uint8_t*
-mapped_file::cend (void) const {
+mapped_file::cend (void) const &
+{
     return data () + size ();
 }
 
diff --git a/io_posix.hpp b/io_posix.hpp
index 4f3e12ee..7af80da6 100644
--- a/io_posix.hpp
+++ b/io_posix.hpp
@@ -35,20 +35,20 @@ namespace util {
 
             ~mapped_file ();
 
-            const uint8_t* data (void) const;
-            uint8_t*       data (void);
-
             bool empty (void) const;
             size_t size (void) const;
 
-            uint8_t* begin (void);
-            uint8_t* end   (void);
+            const uint8_t* data (void) const &;
+            uint8_t*       data (void) &;
 
-            const uint8_t* begin (void) const;
-            const uint8_t* end   (void) const;
+            uint8_t* begin (void) &;
+            uint8_t* end   (void) &;
 
-            const uint8_t* cbegin (void) const;
-            const uint8_t* cend   (void) const;
+            const uint8_t* begin (void) const &;
+            const uint8_t* end   (void) const &;
+
+            const uint8_t* cbegin (void) const &;
+            const uint8_t* cend   (void) const &;
 
             template <typename T> operator util::view<const T *restrict> () const &;
             template <typename T> operator util::view<      T *restrict> ()       &;
diff --git a/io_win32.cpp b/io_win32.cpp
index f1fb7bff..856e697a 100644
--- a/io_win32.cpp
+++ b/io_win32.cpp
@@ -136,22 +136,6 @@ mapped_file::mapped_file (const boost::filesystem::path &path,
 
 
 ///////////////////////////////////////////////////////////////////////////////
-const uint8_t*
-mapped_file::data (void) const
-{
-    return m_data.get ();
-}
-
-
-//-----------------------------------------------------------------------------
-uint8_t*
-mapped_file::data (void)
-{
-    return m_data.get ();
-}
-
-
-//-----------------------------------------------------------------------------
 size_t
 mapped_file::size (void) const
 {
@@ -167,9 +151,25 @@ mapped_file::empty (void) const
 }
 
 
+//-----------------------------------------------------------------------------
+const uint8_t*
+mapped_file::data (void) const &
+{
+    return m_data.get ();
+}
+
+
 //-----------------------------------------------------------------------------
 uint8_t*
-mapped_file::begin (void)
+mapped_file::data (void) &
+{
+    return m_data.get ();
+}
+
+
+//-----------------------------------------------------------------------------
+uint8_t*
+mapped_file::begin (void) &
 {
     return data ();
 }
@@ -177,7 +177,7 @@ mapped_file::begin (void)
 
 //-----------------------------------------------------------------------------
 uint8_t*
-mapped_file::end (void)
+mapped_file::end (void) &
 {
     return data () + size ();
 }
@@ -185,7 +185,7 @@ mapped_file::end (void)
 
 //-----------------------------------------------------------------------------
 const uint8_t*
-mapped_file::begin (void) const
+mapped_file::begin (void) const &
 {
     return cbegin ();
 }
@@ -193,7 +193,7 @@ mapped_file::begin (void) const
 
 //-----------------------------------------------------------------------------
 const uint8_t*
-mapped_file::end (void) const
+mapped_file::end (void) const &
 {
     return cend ();
 }
@@ -201,7 +201,7 @@ mapped_file::end (void) const
 
 //-----------------------------------------------------------------------------
 const uint8_t*
-mapped_file::cbegin (void) const
+mapped_file::cbegin (void) const &
 {
     return data ();
 }
@@ -209,7 +209,7 @@ mapped_file::cbegin (void) const
 
 //-----------------------------------------------------------------------------
 const uint8_t*
-mapped_file::cend (void) const
+mapped_file::cend (void) const &
 {
     return data () + size ();
 }
diff --git a/io_win32.hpp b/io_win32.hpp
index 43f0ce67..73b69c4e 100644
--- a/io_win32.hpp
+++ b/io_win32.hpp
@@ -45,26 +45,23 @@ namespace util {
             mapped_file (const mapped_file&) = delete;
             mapped_file& operator= (const mapped_file&) = delete;
 
-            const uint8_t* data (void) const;
-            uint8_t*       data (void);
-
             size_t size  (void) const;
             bool   empty (void) const;
 
-            uint8_t* begin (void);
-            uint8_t* end   (void);
+            const uint8_t* data (void) const &;
+            uint8_t*       data (void) &;
 
-            const uint8_t* begin (void) const;
-            const uint8_t* end   (void) const;
+            uint8_t* begin (void) &;
+            uint8_t* end   (void) &;
 
-            const uint8_t* cbegin (void) const;
-            const uint8_t* cend   (void) const;
+            const uint8_t* begin (void) const &;
+            const uint8_t* end   (void) const &;
 
-            template <typename T>
-            operator util::view<const T *restrict> () const &;
+            const uint8_t* cbegin (void) const &;
+            const uint8_t* cend   (void) const &;
 
-            template <typename T>
-            operator util::view<T *restrict> () &;
+            template <typename T> operator util::view<const T *restrict> () const &;
+            template <typename T> operator util::view<      T *restrict> ()       &;
 
         private:
             ::util::win32::handle m_file;