From 8f7d60dd21395de0e877534e59a9160e3fde6c89 Mon Sep 17 00:00:00 2001
From: Roland Conybeare <rconybeare@gmail.com>
Date: Fri, 3 May 2024 01:38:21 -0400
Subject: [PATCH] xo-unit: ex1: upgrade to qty::quantity<..> with constexpr
 units

---
 example/ex1/CMakeLists.txt |  1 +
 example/ex1/ex1.cpp        | 23 +++++++++++++++--------
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/example/ex1/CMakeLists.txt b/example/ex1/CMakeLists.txt
index 63c0c8a0..37ce3f44 100644
--- a/example/ex1/CMakeLists.txt
+++ b/example/ex1/CMakeLists.txt
@@ -10,6 +10,7 @@ xo_include_options2(${SELF_EXE})
 # dependencies..
 
 xo_self_headeronly_dependency(${SELF_EXE} xo_unit)
+xo_dependency(${SELF_EXE} xo_flatstring)
 #xo_dependency(${SELF_EXE} reflect)
 
 # end CMakeLists.txt
diff --git a/example/ex1/ex1.cpp b/example/ex1/ex1.cpp
index 27de59ab..d8cd61c5 100644
--- a/example/ex1/ex1.cpp
+++ b/example/ex1/ex1.cpp
@@ -1,22 +1,29 @@
 /** @file ex1.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;
+    using xo::qty::quantity;
     using namespace std;
 
-    auto t = qty::milliseconds(10);
-    auto m = qty::kilograms(2.5);
-    auto a = m / (t*t);
+    constexpr auto t = q::milliseconds(10);
+    constexpr auto m = q::kilograms(2.5);
+
+    constexpr auto t2 = t*t;
+#ifdef NOT_YET
+    constexpr auto a = m / (t*t);
 
     static_assert(same_as<decltype(t), quantity<u::millisecond, int>>);
+#endif
 
-    cerr << "t: " << t << ", m: " << m << ", m.t^-2: " << a << endl;
+    cerr << "t: " << t << ", m: " << m
+         << ", t^2: " << t2
+        //<< ", m.t^-2: " << a
+         << endl;
 }
 
 /** end ex1.cpp **/