diff --git a/example/ex2/ex2.cpp b/example/ex2/ex2.cpp
index f2116570..af2e80dd 100644
--- a/example/ex2/ex2.cpp
+++ b/example/ex2/ex2.cpp
@@ -38,4 +38,5 @@ main () {
     cerr << "a3: " << a3 << endl;
 }
 
+
 /** end ex2.cpp **/
diff --git a/example/ex3/ex3.cpp b/example/ex3/ex3.cpp
index d13343f3..36073e1a 100644
--- a/example/ex3/ex3.cpp
+++ b/example/ex3/ex3.cpp
@@ -8,14 +8,13 @@ int
 main () {
     namespace q = xo::qty::qty;
     namespace u = xo::qty::nu;
-    using xo::qty::with_units;
     using xo::qty::stdquantity;
     using xo::qty::quantity;
     using xo::flatstring;
     using namespace std;
 
-    constexpr stdquantity<u::second> t = q::minutes(2);
-    constexpr stdquantity<u::meter> d = q::kilometers(2.5);
+    constexpr stdquantity<double, u::second> t = q::minutes(2);
+    constexpr stdquantity<double, u::meter> d = q::kilometers(2.5);
 
     constexpr auto t2 = t*t;
     constexpr auto a = d / (t*t);
diff --git a/include/xo/unit/quantity.hpp b/include/xo/unit/quantity.hpp
index 25558491..fe74c809 100644
--- a/include/xo/unit/quantity.hpp
+++ b/include/xo/unit/quantity.hpp
@@ -157,8 +157,9 @@ namespace xo {
             Repr scale_ = Repr{};
         };
 
-        template <natural_unit<::std::int64_t> NaturalUnit = natural_unit<::std::int64_t>()>
-        using stdquantity = xo::qty::quantity<double, ::std::int64_t, NaturalUnit>;
+        template <typename Repr = double,
+                  natural_unit<std::int64_t> NaturalUnit = natural_unit<std::int64_t>()>
+        using stdquantity = quantity<Repr, std::int64_t, NaturalUnit>;
 
         template <typename Quantity, typename Int, typename Int2x>
         constexpr auto