From dd643109ccd48faa594a156fd39d9e281d7953a9 Mon Sep 17 00:00:00 2001
From: Roland Conybeare <rconybeare@gmail.com>
Date: Fri, 3 May 2024 18:45:37 -0400
Subject: [PATCH] xo-unit: streamlined ex2

---
 example/ex2/CMakeLists.txt |  2 +-
 example/ex2/ex2.cpp        | 37 +++++++++++++++++++++++++++++--------
 2 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/example/ex2/CMakeLists.txt b/example/ex2/CMakeLists.txt
index 608daf93..339ba922 100644
--- a/example/ex2/CMakeLists.txt
+++ b/example/ex2/CMakeLists.txt
@@ -10,6 +10,6 @@ xo_include_options2(${SELF_EXE})
 # dependencies..
 
 xo_self_headeronly_dependency(${SELF_EXE} xo_unit)
-#xo_dependency(${SELF_EXE} reflect)
+xo_dependency(${SELF_EXE} xo_flatstring)
 
 # end CMakeLists.txt
diff --git a/example/ex2/ex2.cpp b/example/ex2/ex2.cpp
index 52b65a58..3fc1c94f 100644
--- a/example/ex2/ex2.cpp
+++ b/example/ex2/ex2.cpp
@@ -1,20 +1,41 @@
 /** @file ex2.cpp **/
 
-#include "xo/unit/mpl/quantity.hpp"
+#include "xo/unit/quantity.hpp"
+#include "xo/unit/quantity_iostream.hpp"
 #include <iostream>
 
 int
 main () {
-    namespace u = xo::unit::units;
-    namespace qty = xo::unit::qty;
-    using xo::unit::quantity;
+    namespace q = xo::qty::qty;
+    namespace su = xo::qty::su;
+    using xo::qty::with_units;
+    using xo::qty::quantity;
+    using xo::flatstring;
     using namespace std;
 
-    quantity<u::second> t = qty::milliseconds(10);
-    quantity<u::gram> m = qty::kilograms(2.5);
-    auto a = m / (t*t);
+    constexpr auto t = q::minutes(2);
+    constexpr auto d = q::kilometers(2.5);
 
-    cerr << "t: " << t << ", m: " << m << ", m.t^-2: " << a << endl;
+    constexpr auto t2 = t*t;
+    constexpr auto a = d / (t*t);
+
+    cerr << "t: " << t << ", d: " << d
+         << ", t^2: " << t2
+         << ", d.t^-2: " << a
+         << endl;
+
+    constexpr auto a2 = a.template rescale<su::meter / (su::second * su::second)>();
+
+    static_assert(a2.abbrev() == flatstring("m.s^-2"));
+
+    cerr << "a2: " << a2 << endl;
+
+    constexpr auto au = q::meter / (q::second * q::second);
+    constexpr auto a3 = with_units(a, au);
+
+    static_assert(a3.abbrev() == flatstring("m.s^-2"));
+
+    cerr << "a3: " << a3 << endl;
 }
 
 /** end ex2.cpp **/