diff --git a/region.cpp b/region.cpp
index edba9e54..5ecae38c 100644
--- a/region.cpp
+++ b/region.cpp
@@ -27,6 +27,13 @@
 #include <type_traits>
 
 
+//-----------------------------------------------------------------------------
+template <typename T>
+util::region<T>::region (util::extent<size_type> _extent):
+    region (util::point<2,T>::ORIGIN, _extent)
+{ ; }
+
+
 //-----------------------------------------------------------------------------
 template <typename T>
 util::region<T>::region (point<2,T> _point,
@@ -42,10 +49,7 @@ util::region<T>::region (point<2,T> _point,
 template <typename T>
 util::region<T>::region (point<2,T> _a,
                          point<2,T> _b):
-    x (_a.x),
-    y (_a.y),
-    w (_b.x - _a.x),
-    h (_b.y - _a.y)
+    region (_a, _b - _a)
 {
     CHECK_GE (_b.x, _a.x);
     CHECK_GE (_b.y, _a.y);
@@ -57,10 +61,7 @@ util::region<T>::region (position_type _x,
                          position_type _y,
                          size_type _w,
                          size_type _h):
-    x (_x),
-    y (_y),
-    w (_w),
-    h (_h)
+    region (point<2,T> {_x, _y}, extent<T> {_w, _h})
 { ; }
 
 
@@ -85,7 +86,7 @@ util::region<T>::diameter (void) const
 //-----------------------------------------------------------------------------
 template <typename T>
 util::extent<typename util::region<T>::size_type>
-util::region<T>::size (void) const
+util::region<T>::magnitude (void) const
 {
     return { w, h };
 }
diff --git a/region.hpp b/region.hpp
index ffdbcfdf..3815d796 100644
--- a/region.hpp
+++ b/region.hpp
@@ -43,13 +43,14 @@ namespace util {
         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 (T _x, T _y, size_type _w, size_type _h);
 
         size_type area     (void) const;
         size_type diameter (void) const;
-        util::extent<size_type>  size (void) const;
+        util::extent<size_type>  magnitude (void) const;
 
         void scale (T factor);