diff --git a/debug.hpp b/debug.hpp
index 3bf9b617..85df0b2e 100644
--- a/debug.hpp
+++ b/debug.hpp
@@ -304,15 +304,23 @@ namespace debug {
     bool valid (const T&);
 
 
-    template <template<typename> class T, typename ...Args>
+    template <
+        template<size_t, typename...> class T,
+        size_t S,
+        typename ...Args
+    >
     struct validator {
-        static bool is_valid (const T<Args...>&);
+        static bool is_valid (const T<S,Args...>&);
     };
 
 
-    template <template<typename> class T, typename ...Args>
-    bool valid (const T<Args...> &v)
-    { return validator<T,Args...>::is_valid (v); }
+    template <
+        template<size_t,typename...> class T,
+        size_t S,
+        typename ...Args
+    >
+    bool valid (const T<S,Args...> &v)
+    { return validator<T,S,Args...>::is_valid (v); }
 
 
     template <typename T>
@@ -320,7 +328,10 @@ namespace debug {
     { CHECK (valid (t)); }
 
 
-    template <template<typename> class T, typename ...Args>
+    template <
+        template<typename...> class T,
+        typename ...Args
+    >
     void sanity (const T<Args...> &t)
     { CHECK (valid (t)); }
 }
diff --git a/extent.cpp b/extent.cpp
index 810ab828..ec44ed43 100644
--- a/extent.cpp
+++ b/extent.cpp
@@ -25,42 +25,44 @@
 #include <cmath>
 
 ///////////////////////////////////////////////////////////////////////////////
-template <typename T>
-util::extent<T>::extent (const T  _width, const T  _height):
+template <size_t S, typename T>
+util::extent<S,T>::extent (const T  _width, const T  _height):
         w (_width),
         h (_height)
 {
+    static_assert (S == 2, "extents currently only support 2 dimensions");
+
     CHECK_GE (w, 0);
     CHECK_GE (h, 0);
 }
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::extent<T>::extent (T t):
+template <size_t S, typename T>
+util::extent<S,T>::extent (T t):
     extent (t, t)
 { ; }
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::extent<T>::extent (vector<2,T> _v):
+template <size_t S, typename T>
+util::extent<S,T>::extent (vector<S,T> _v):
     extent (_v.x, _v.y)
 { ; }
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::extent<T>::extent (const util::extent<T> &rhs):
+template <size_t S, typename T>
+util::extent<S,T>::extent (const util::extent<S,T> &rhs):
         w (rhs.w),
         h (rhs.h)
 { ; }
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::extent<T>&
-util::extent<T>::operator= (const util::extent<T> &rhs)
+template <size_t S, typename T>
+util::extent<S,T>&
+util::extent<S,T>::operator= (extent<S,T> rhs)
 {
     w = rhs.w;
     h = rhs.h;
@@ -70,27 +72,27 @@ util::extent<T>::operator= (const util::extent<T> &rhs)
 
 
 ///////////////////////////////////////////////////////////////////////////////
-template <typename T>
+template <size_t S, typename T>
 T
-util::extent<T>::diameter (void) const
+util::extent<S,T>::diameter (void) const
 {
     return static_cast<T> (sqrt (w * w + h * h));
 }
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
+template <size_t S, typename T>
 T
-util::extent<T>::area (void) const
+util::extent<S,T>::area (void) const
 {
     return w * h;
 }
 
 
 ///////////////////////////////////////////////////////////////////////////////
-template <typename T>
-util::extent<T>
-util::extent<T>::expanded (util::vector<2,T> mag) const
+template <size_t S, typename T>
+util::extent<S,T>
+util::extent<S,T>::expanded (util::vector<S,T> mag) const
 {
     return {
         w + mag.x,
@@ -100,36 +102,36 @@ util::extent<T>::expanded (util::vector<2,T> mag) const
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::extent<T>
-util::extent<T>::expanded (T t) const
+template <size_t S, typename T>
+util::extent<S,T>
+util::extent<S,T>::expanded (T t) const
 {
-    return expanded (util::vector<2,T> {t});
+    return expanded (util::vector<S,T> {t});
 }
 
 
 ///////////////////////////////////////////////////////////////////////////////
-template <typename T>
+template <size_t S, typename T>
 float
-util::extent<T>::aspect (void) const
+util::extent<S,T>::aspect (void) const
 {
     return static_cast<float> (w) / static_cast<float> (h);
 }
 
 
 ///////////////////////////////////////////////////////////////////////////////
-template <typename T>
+template <size_t S, typename T>
 bool
-util::extent<T>::empty (void) const
+util::extent<S,T>::empty (void) const
 {
     return almost_equal (area(), 0);
 }
 
 
 ///////////////////////////////////////////////////////////////////////////////
-template <typename T>
+template <size_t S, typename T>
 T&
-util::extent<T>::operator[] (size_t idx)
+util::extent<S,T>::operator[] (size_t idx)
 {
     switch (idx) {
     case 0: return w;
@@ -142,9 +144,9 @@ util::extent<T>::operator[] (size_t idx)
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
+template <size_t S, typename T>
 const T&
-util::extent<T>::operator[] (size_t idx) const
+util::extent<S,T>::operator[] (size_t idx) const
 {
     switch (idx) {
     case 0: return w;
@@ -157,18 +159,18 @@ util::extent<T>::operator[] (size_t idx) const
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
+template <size_t S, typename T>
 size_t
-util::extent<T>::size (void) const
+util::extent<S,T>::size (void) const
 {
-    return 2u;
+    return S;
 }
 
 
 ///////////////////////////////////////////////////////////////////////////////
-template <typename T>
+template <size_t S, typename T>
 bool
-util::extent<T>::operator ==(const extent& rhs) const
+util::extent<S,T>::operator ==(const extent& rhs) const
 {
     return almost_equal (w, rhs.w) &&
            almost_equal (h, rhs.h);
@@ -176,15 +178,15 @@ util::extent<T>::operator ==(const extent& rhs) const
 
 
 ///////////////////////////////////////////////////////////////////////////////
-template <typename T>
-const util::extent<T> util::extent<T>::MIN {
+template <size_t S, typename T>
+const util::extent<S,T> util::extent<S,T>::MIN {
     0, 0
 };
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-const util::extent<T> util::extent<T>::MAX {
+template <size_t S, typename T>
+const util::extent<S,T> util::extent<S,T>::MAX {
     std::numeric_limits<T>::max (),
     std::numeric_limits<T>::max ()
 };
@@ -192,43 +194,43 @@ const util::extent<T> util::extent<T>::MAX {
 
 ///////////////////////////////////////////////////////////////////////////////
 namespace debug {
-    template <typename T>
-    struct validator<util::extent,T> {
-        static bool is_valid (const util::extent<T> &e)
+    template <size_t S, typename T>
+    struct validator<util::extent,S,T> {
+        static bool is_valid (const util::extent<S,T> &e)
         {
             return e.w >= 0 && e.h >= 0;
         }
     };
 }
 
-template bool debug::valid (const util::extent<float>&);
-template bool debug::valid (const util::extent<double>&);
-template bool debug::valid (const util::extent<uint16_t>&);
-template bool debug::valid (const util::extent<uint32_t>&);
-template bool debug::valid (const util::extent<uint64_t>&);
+template bool debug::valid (const util::extent<2,float>&);
+template bool debug::valid (const util::extent<2,double>&);
+template bool debug::valid (const util::extent<2,uint16_t>&);
+template bool debug::valid (const util::extent<2,uint32_t>&);
+template bool debug::valid (const util::extent<2,uint64_t>&);
 
 
 ///////////////////////////////////////////////////////////////////////////////
-template <typename T>
+template <size_t S, typename T>
 std::ostream&
-util::operator<< (std::ostream &os, util::extent<T> e)
+util::operator<< (std::ostream &os, util::extent<S,T> e)
 {
     os << "[" << e.w << ", " << e.h << "]";
     return os;
 }
 
 
-template std::ostream& util::operator<< (std::ostream&, util::extent<uint16_t>);
-template std::ostream& util::operator<< (std::ostream&, util::extent<uint32_t>);
-template std::ostream& util::operator<< (std::ostream&, util::extent<uint64_t>);
-template std::ostream& util::operator<< (std::ostream&, util::extent<float>);
-template std::ostream& util::operator<< (std::ostream&, util::extent<double>);
+template std::ostream& util::operator<< (std::ostream&, util::extent<2,uint16_t>);
+template std::ostream& util::operator<< (std::ostream&, util::extent<2,uint32_t>);
+template std::ostream& util::operator<< (std::ostream&, util::extent<2,uint64_t>);
+template std::ostream& util::operator<< (std::ostream&, util::extent<2,float>);
+template std::ostream& util::operator<< (std::ostream&, util::extent<2,double>);
 
 
 //-----------------------------------------------------------------------------
 namespace util {
-    template struct extent<uint32_t>;
-    template struct extent<uint64_t>;
-    template struct extent<float>;
-    template struct extent<double>;
+    template struct extent<2,uint32_t>;
+    template struct extent<2,uint64_t>;
+    template struct extent<2,float>;
+    template struct extent<2,double>;
 }
diff --git a/extent.hpp b/extent.hpp
index 244ebd2b..0eee6111 100644
--- a/extent.hpp
+++ b/extent.hpp
@@ -29,22 +29,22 @@ namespace util {
     /**
      * A pure two-dimensional size, without positioning
      */
-    template <typename T>
+    template <size_t S, typename T>
     struct extent {
         T w, h;
 
         extent (const T  _width, const T  _height);
         extent (T);
-        extent (vector<2,T>);
+        extent (vector<S,T>);
         extent (const extent&);
-        extent& operator= (const extent&);
+        extent& operator= (extent);
         extent () = default;
 
         T    area  (void) const;
         T diameter (void) const;
 
-        extent<T> expanded (util::vector<2,T>) const;
-        extent<T> expanded (T) const;
+        extent expanded (vector<S,T>) const;
+        extent expanded (T) const;
 
         float aspect (void) const;
 
@@ -60,18 +60,18 @@ namespace util {
             { return !(*this == rhs); }
 
         template <typename U>
-        extent<U> cast (void) const;
+        extent<S,U> cast (void) const;
 
-        static const extent<T> MAX;
-        static const extent<T> MIN;
+        static const extent MAX;
+        static const extent MIN;
     };
 
-    typedef extent<int> extent2i;
-    typedef extent<size_t> extent2u;
-    typedef extent<float> extent2f;
+    typedef extent<2,int> extent2i;
+    typedef extent<2,size_t> extent2u;
+    typedef extent<2,float> extent2f;
 
-    template <typename T>
-    std::ostream& operator<< (std::ostream&, util::extent<T>);
+    template <size_t S, typename T>
+    std::ostream& operator<< (std::ostream&, util::extent<S,T>);
 }
 
 
diff --git a/extent.ipp b/extent.ipp
index ac91d88d..b01f5cd3 100644
--- a/extent.ipp
+++ b/extent.ipp
@@ -25,10 +25,10 @@
 #define __UTIL_EXTENT_IPP
 
 //-----------------------------------------------------------------------------
-template <typename T>
+template <size_t S, typename T>
 template <typename U>
-util::extent<U>
-util::extent<T>::cast (void) const
+util::extent<S,U>
+util::extent<S,T>::cast (void) const
 {
     return {
         static_cast<U> (w),
diff --git a/region.cpp b/region.cpp
index 3db6ce6d..a30f37c1 100644
--- a/region.cpp
+++ b/region.cpp
@@ -28,16 +28,16 @@
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::region<T>::region (util::extent<size_type> _extent):
-    region (util::point<2,T>::ORIGIN, _extent)
+template <size_t S, typename T>
+util::region<S,T>::region (extent_t _extent):
+    region (point_t::ORIGIN, _extent)
 { ; }
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::region<T>::region (point<2,T> _point,
-                         extent<size_type> _size):
+template <size_t S, typename T>
+util::region<S,T>::region (point_t _point,
+                         extent_t _size):
     x (_point.x),
     y (_point.y),
     w (_size.w),
@@ -46,9 +46,9 @@ util::region<T>::region (point<2,T> _point,
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::region<T>::region (point<2,T> _a,
-                         point<2,T> _b):
+template <size_t S, typename T>
+util::region<S,T>::region (point_t _a,
+                         point_t _b):
     region (_a, _b - _a)
 {
     CHECK_GE (_b.x, _a.x);
@@ -56,46 +56,46 @@ util::region<T>::region (point<2,T> _a,
 }
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::region<T>::region (position_type _x,
+template <size_t S, typename T>
+util::region<S,T>::region (position_type _x,
                          position_type _y,
                          size_type _w,
                          size_type _h):
-    region (point<2,T> {_x, _y}, extent<T> {_w, _h})
+    region (point_t {_x, _y}, extent<S,T> {_w, _h})
 { ; }
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-typename util::region<T>::size_type
-util::region<T>::area (void) const
+template <size_t S, typename T>
+typename util::region<S,T>::size_type
+util::region<S,T>::area (void) const
 {
     return w * h;
 }
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-typename util::region<T>::size_type
-util::region<T>::diameter (void) const
+template <size_t S, typename T>
+typename util::region<S,T>::size_type
+util::region<S,T>::diameter (void) const
 {
     return static_cast<size_type> (std::sqrt (w * w + h * h));
 }
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-typename util::region<T>::extent_t
-util::region<T>::magnitude (void) const
+template <size_t S, typename T>
+typename util::region<S,T>::extent_t
+util::region<S,T>::magnitude (void) const
 {
     return { w, h };
 }
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-typename util::region<T>::extent_t
-util::region<T>::magnitude (extent_t e)
+template <size_t S, typename T>
+typename util::region<S,T>::extent_t
+util::region<S,T>::magnitude (extent_t e)
 {
     w = e.w;
     h = e.h;
@@ -105,9 +105,9 @@ util::region<T>::magnitude (extent_t e)
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
+template <size_t S, typename T>
 void
-util::region<T>::scale (T factor)
+util::region<S,T>::scale (T factor)
 {
     x -= (w * factor - w) / T{2};
     y -= (h * factor - h) / T{2};
@@ -118,18 +118,18 @@ util::region<T>::scale (T factor)
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
+template <size_t S, typename T>
 bool
-util::region<T>::empty (void) const
+util::region<S,T>::empty (void) const
 {
     return almost_zero (area ());
 }
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::point<2,T>
-util::region<T>::rebase (util::point<2,T> p)
+template <size_t S, typename T>
+typename util::region<S,T>::point_t
+util::region<S,T>::rebase (point_t p)
 {
     x = p.x;
     y = p.y;
@@ -139,39 +139,39 @@ util::region<T>::rebase (util::point<2,T> p)
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::point<2,T>
-util::region<T>::base (void) const
+template <size_t S, typename T>
+typename util::region<S,T>::point_t
+util::region<S,T>::base (void) const
 {
     return { x, y };
 }
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::point<2,T>
-util::region<T>::away (void) const
+template <size_t S, typename T>
+typename util::region<S,T>::point_t
+util::region<S,T>::away (void) const
 {
     return { x + w, y + h };
 }
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::point<2,T>
-util::region<T>::centre (void) const
+template <size_t S, typename T>
+typename util::region<S,T>::point_t
+util::region<S,T>::centre (void) const
 {
     T cx = x + w / T{2},
       cy = y + h / T{2};
 
-    return point<2,T> { cx, cy };
+    return point_t { cx, cy };
 }
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::point<2,T>
-util::region<T>::closest (point<2,T> p) const
+template <size_t S, typename T>
+typename util::region<S,T>::point_t
+util::region<S,T>::closest (point_t p) const
 {
     return {
         p.x < x     ? x     :
@@ -186,9 +186,9 @@ util::region<T>::closest (point<2,T> p) const
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
+template <size_t S, typename T>
 bool
-util::region<T>::includes (const point<2,T> &p) const
+util::region<S,T>::includes (point_t p) const
 {
     return p.x >= x &&
            p.y >= y &&
@@ -198,9 +198,9 @@ util::region<T>::includes (const point<2,T> &p) const
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
+template <size_t S, typename T>
 bool
-util::region<T>::contains (const point<2,T> &p) const
+util::region<S,T>::contains (point_t p) const
 {
     return p.x > x &&
            p.y > y &&
@@ -212,9 +212,9 @@ util::region<T>::contains (const point<2,T> &p) const
 //-----------------------------------------------------------------------------
 // FIXME: This will fail with an actual infinite range (NaNs will be generated
 // in the conditionals).
-template <typename T>
+template <size_t S, typename T>
 bool
-util::region<T>::intersects (const util::region<T> &rhs) const
+util::region<S,T>::intersects (region<S,T> rhs) const
 {
     return  x     < rhs.x + rhs.w &&
             rhs.x < x     +     w &&
@@ -224,9 +224,9 @@ util::region<T>::intersects (const util::region<T> &rhs) const
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
+template <size_t S, typename T>
 void
-util::region<T>::constrain (point<2,T> &p) const
+util::region<S,T>::constrain (point_t &p) const
 {
     p.x = std::min (std::max (p.x, x), x + w);
     p.y = std::min (std::max (p.y, y), y + h);
@@ -234,11 +234,11 @@ util::region<T>::constrain (point<2,T> &p) const
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::point<2,T>
-util::region<T>::constrained (const point<2,T> &p) const
+template <size_t S, typename T>
+typename util::region<S,T>::point_t
+util::region<S,T>::constrained (point_t p) const
 {
-    point<2,T> v;
+    point_t v;
     v.x = std::min (std::max (p.x, x), x + w);
     v.y = std::min (std::max (p.y, y), y + h);
 
@@ -247,9 +247,9 @@ util::region<T>::constrained (const point<2,T> &p) const
 
 
 //-----------------------------------------------------------------------------
-template<typename T>
-util::region<T>
-util::region<T>::intersection (const util::region<T> &rhs) const
+template<size_t S, typename T>
+util::region<S,T>
+util::region<S,T>::intersection (region<S,T> rhs) const
 {
     T newx1 = max (x, rhs.x),
       newy1 = max (y, rhs.y),
@@ -261,14 +261,14 @@ util::region<T>::intersection (const util::region<T> &rhs) const
 
     size_type nw = sign_cast<size_type> (newx2 - newx1);
     size_type nh = sign_cast<size_type> (newy2 - newy1);
-    return util::region<T> (newx1, newy1, nw, nh);
+    return util::region<S,T> (newx1, newy1, nw, nh);
 }
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::region<T>
-util::region<T>::inset (T mag)
+template <size_t S, typename T>
+util::region<S,T>
+util::region<S,T>::inset (T mag)
 {
     CHECK_GE (w, 2 * mag);
     CHECK_GE (h, 2 * mag);
@@ -278,9 +278,9 @@ util::region<T>::inset (T mag)
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::region<T>&
-util::region<T>::expand (T _w, T _h)
+template <size_t S, typename T>
+util::region<S,T>&
+util::region<S,T>::expand (T _w, T _h)
 {
     x -= _w;
     y -= _h;
@@ -292,18 +292,18 @@ util::region<T>::expand (T _w, T _h)
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::region<T>&
-util::region<T>::expand (T mag)
+template <size_t S, typename T>
+util::region<S,T>&
+util::region<S,T>::expand (T mag)
 {
     return expand (mag, mag);
 }
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::region<T>
-util::region<T>::expanded (T _w, T _h) const
+template <size_t S, typename T>
+util::region<S,T>
+util::region<S,T>::expanded (T _w, T _h) const
 {
     return {
         x - _w,
@@ -315,36 +315,36 @@ util::region<T>::expanded (T _w, T _h) const
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::region<T>
-util::region<T>::expanded (T mag) const
+template <size_t S, typename T>
+util::region<S,T>
+util::region<S,T>::expanded (T mag) const
 {
     return expanded (mag, mag);
 }
 
 
 ///////////////////////////////////////////////////////////////////////////////
-template <typename T>
-util::region<T>
-util::region<T>::operator+ (vector<2,T> rhs) const
+template <size_t S, typename T>
+util::region<S,T>
+util::region<S,T>::operator+ (vector<S,T> rhs) const
 {
     return { x + rhs.x, y + rhs.y, w, h };
 }
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
-util::region<T>
-util::region<T>::operator- (vector<2,T> rhs) const
+template <size_t S, typename T>
+util::region<S,T>
+util::region<S,T>::operator- (vector<S,T> rhs) const
 {
     return { x - rhs.x, y - rhs.y, w, h };
 }
 
 
 ///////////////////////////////////////////////////////////////////////////////
-template <typename T>
+template <size_t S, typename T>
 bool
-util::region<T>::operator== (const region& rhs) const
+util::region<S,T>::operator== (region rhs) const
 {
     return almost_equal (x, rhs.x) &&
            almost_equal (y, rhs.y) &&
@@ -354,9 +354,9 @@ util::region<T>::operator== (const region& rhs) const
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
+template <size_t S, typename T>
 void
-util::region<T>::sanity (void) const {
+util::region<S,T>::sanity (void) const {
     CHECK_GE (w, 0);
     CHECK_GE (h, 0);
     static_assert(!std::is_floating_point<T>::value,
@@ -367,14 +367,14 @@ util::region<T>::sanity (void) const {
 //-----------------------------------------------------------------------------
 namespace util {
     template <>
-    void region<double>::sanity (void) const {
+    void region<2,double>::sanity (void) const {
         CHECK_GE (w, 0);
         CHECK_GE (h, 0);
     }
 
 
     template <>
-    void region<float>::sanity (void) const {
+    void region<2,float>::sanity (void) const {
         CHECK_GE (w, 0);
         CHECK_GE (h, 0);
     }
@@ -389,9 +389,9 @@ namespace util {
 ///
 /// Specifically does not allow infinities. Use/define INFINITE when required.
 
-template <typename T>
-const util::region<T>
-util::region<T>::MAX (
+template <size_t S, typename T>
+const util::region<S,T>
+util::region<S,T>::MAX (
     std::numeric_limits<T>::lowest () / 2,
     std::numeric_limits<T>::lowest () / 2,
     std::numeric_limits<T>::max (),
@@ -399,15 +399,15 @@ util::region<T>::MAX (
 );
 
 
-template  <typename T>
-const util::region<T>
-util::region<T>::UNIT (0, 0, 1, 1);
+template  <size_t S, typename T>
+const util::region<S,T>
+util::region<S,T>::UNIT (0, 0, 1, 1);
 
 
 //-----------------------------------------------------------------------------
-template <typename T>
+template <size_t S, typename T>
 std::ostream&
-util::operator<< (std::ostream &os, const util::region<T> &rhs) {
+util::operator<< (std::ostream &os, const util::region<S,T> &rhs) {
     os << "region(" << rhs.x << ", " << rhs.y << ", " << rhs.w << ", " << rhs.h << ")";
     return os;
 }
@@ -415,15 +415,15 @@ util::operator<< (std::ostream &os, const util::region<T> &rhs) {
 
 //-----------------------------------------------------------------------------
 namespace util {
-    template struct region<uint32_t>;
-    template struct region<uint64_t>;
-    template struct region<float>;
-    template struct region<double>;
+    template struct region<2,uint32_t>;
+    template struct region<2,uint64_t>;
+    template struct region<2,float>;
+    template struct region<2,double>;
 
-    template std::ostream& operator<< (std::ostream&, const region< int32_t>&);
-    template std::ostream& operator<< (std::ostream&, const region< int64_t>&);
-    template std::ostream& operator<< (std::ostream&, const region<uint32_t>&);
-    template std::ostream& operator<< (std::ostream&, const region<uint64_t>&);
-    template std::ostream& operator<< (std::ostream&, const region<   float>&);
-    template std::ostream& operator<< (std::ostream&, const region<  double>&);
+    template std::ostream& operator<< (std::ostream&, const region<2, int32_t>&);
+    template std::ostream& operator<< (std::ostream&, const region<2, int64_t>&);
+    template std::ostream& operator<< (std::ostream&, const region<2,uint32_t>&);
+    template std::ostream& operator<< (std::ostream&, const region<2,uint64_t>&);
+    template std::ostream& operator<< (std::ostream&, const region<2,   float>&);
+    template std::ostream& operator<< (std::ostream&, const region<2,  double>&);
 }
diff --git a/region.hpp b/region.hpp
index 125ac2de..840ebdc8 100644
--- a/region.hpp
+++ b/region.hpp
@@ -30,25 +30,25 @@ namespace util {
     /**
      * A two-dimensional rectangle, with size and position.
      */
-    template <typename T>
+    template <size_t S, typename T>
     struct region {
         using position_type = T;
         using size_type = typename try_unsigned<T>::type;
 
-        static constexpr size_t dimension = 2u;
+        static constexpr size_t dimension = S;
         static constexpr size_t elements = dimension * 2;
         using value_type = T;
 
-        using extent_t = util::extent<size_type>;
-        using point_t  = util::point<2,T>;
+        using extent_t = util::extent<S,size_type>;
+        using point_t  = util::point<S,position_type>;
 
         position_type x, y;
         size_type w, h;
 
         region () = default;
-        region (util::extent<size_type>);
-        region (util::point<2,T>, util::extent<size_type>);
-        region (util::point<2,T>, util::point<2,T>);
+        region (extent_t);
+        region (point_t, extent_t);
+        region (point_t, point_t);
         region (T _x, T _y, size_type _w, size_type _h);
 
         size_type area     (void) const;
@@ -60,24 +60,24 @@ namespace util {
 
         bool empty (void) const;
 
-        point<2,T> rebase (util::point<2,T>);
+        point_t rebase (point_t);
 
-        point<2,T> base    (void) const;
-        point<2,T> away    (void) const;
-        point<2,T> centre  (void) const;
-        point<2,T> closest (point<2,T>) const;
+        point_t base    (void) const;
+        point_t away    (void) const;
+        point_t centre  (void) const;
+        point_t closest (point_t) const;
 
         // Point and region relation queries
-        bool includes (const point<2,T>&) const; // inclusive of borders
-        bool contains (const point<2,T>&) const; // exclusive of borders
-        bool intersects (const region<T>&) const;  // exclusive of borders
+        bool includes (point_t) const; // inclusive of borders
+        bool contains (point_t) const; // exclusive of borders
+        bool intersects (region<S,T>) const;  // exclusive of borders
 
         // Move a point to be within the region bounds
-        void constrain (point<2,T>&) const;
-        point<2,T> constrained (const point<2,T>&) const;
+        void constrain (point_t&) const;
+        point_t constrained (point_t) const;
 
         // Compute binary region combinations
-        region intersection (const region<T>&) const;
+        region intersection (region<S,T>) const;
 
         // Compute a region `mag` units into the region
         region inset (T mag);
@@ -89,27 +89,28 @@ namespace util {
         region& expand (T w, T h);
 
         // arithmetic operators
-        region operator+ (vector<2,T>) const;
-        region operator- (vector<2,T>) const;
+        region operator+ (vector<S,T>) const;
+        region operator- (vector<S,T>) const;
 
         // Logical comparison operators
-        bool operator ==(const region<T>& rhs) const;
-        bool operator !=(const region<T>& rhs) const
+        bool operator ==(region<S,T> rhs) const;
+        bool operator !=(region<S,T> rhs) const
             { return !(*this == rhs); }
 
         // Utility constants
-        static const region<T> MAX;
-        static const region<T> UNIT;
+        static const region<S,T> MAX;
+        static const region<S,T> UNIT;
 
         void sanity (void) const;
     };
 
-    typedef region<size_t>   region2u;
-    typedef region<intmax_t> region2i;
-    typedef region<float>    region2f;
+    typedef region<2,size_t>   region2u;
+    typedef region<2,intmax_t> region2i;
+    typedef region<2,float>    region2f;
+    typedef region<2,double>   region2d;
 
-    template <typename T>
-    std::ostream& operator<< (std::ostream&, const util::region<T>&);
+    template <size_t S, typename T>
+    std::ostream& operator<< (std::ostream&, const util::region<S,T>&);
 }
 
 
diff --git a/test/extent.cpp b/test/extent.cpp
index 40ee0f56..def7f591 100644
--- a/test/extent.cpp
+++ b/test/extent.cpp
@@ -4,5 +4,6 @@
 int
 main (void)
 {
-    debug::sanity (util::extent<float> {0, 0});
+    // Simple symbol visibility check
+    util::extent2f instance;
 }
diff --git a/test/region.cpp b/test/region.cpp
index 7c86a490..d0b3aa5a 100644
--- a/test/region.cpp
+++ b/test/region.cpp
@@ -2,35 +2,33 @@
 #include "../point.hpp"
 #include "../debug.hpp"
 
-using util::region;
-using util::point;
-using util::point2d;
+using namespace util;
 
 int
 main (int, char **) {
     {
-         region<double> a (32.7, -6.09703, 0.8, 2);
-         region<double> b (33.5, -4.5,     0.5, 0.5);
+         region2d a {32.7, -6.09703, 0.8, 2};
+         region2d b {33.5, -4.5,     0.5, 0.5};
 
          CHECK (!a.intersects (b));
     }
 
-    CHECK (region<double>::MAX.intersects (region<double>::UNIT));
-    CHECK (region< float>::MAX.intersects (region< float>::UNIT));
+    CHECK (region2d::MAX.intersects (region2d::UNIT));
+    CHECK (region2f::MAX.intersects (region2f::UNIT));
 
-    CHECK_EQ (region<double>::UNIT.area (), 1.0);
-    CHECK_EQ (region< float>::UNIT.area (), 1.0f);
+    CHECK_EQ (region2d::UNIT.area (), 1.0);
+    CHECK_EQ (region2f::UNIT.area (), 1.0f);
 
-    CHECK (region<unsigned> (0, 0, 2, 2).includes (point<2,unsigned>(1, 1)));
-    CHECK (region<unsigned> (0, 0, 2, 2).includes (point<2,unsigned>(0, 0)));
-    CHECK (region<unsigned> (0, 0, 2, 2).includes (point<2,unsigned>(2, 2)));
+    CHECK (region2u (0, 0, 2, 2).includes (point2u {1, 1}));
+    CHECK (region2u (0, 0, 2, 2).includes (point2u {0, 0}));
+    CHECK (region2u (0, 0, 2, 2).includes (point2u {2, 2}));
 
-    CHECK ( region<unsigned> (0, 0, 2, 2).contains (point<2,unsigned>(1, 1)));
-    CHECK (!region<unsigned> (0, 0, 2, 2).contains (point<2,unsigned>(0, 0)));
-    CHECK (!region<unsigned> (0, 0, 2, 2).contains (point<2,unsigned>(2, 2)));
+    CHECK ( region2u (0, 0, 2, 2).contains (point2u {1, 1}));
+    CHECK (!region2u (0, 0, 2, 2).contains (point2u {0, 0}));
+    CHECK (!region2u (0, 0, 2, 2).contains (point2u {2, 2}));
 
-    //CHECK (region<intmax_t> (0, 0, 10, 10).includes (point2d (0.4, 0.01)));
-    //CHECK (region<intmax_t> (0, 0, 10, 10).contains (point2d (0.4, 0.01)));
+    //CHECK (region<2,intmax_t> (0, 0, 10, 10).includes (point2d (0.4, 0.01)));
+    //CHECK (region<2,intmax_t> (0, 0, 10, 10).contains (point2d (0.4, 0.01)));
 
     return 0;
 }