From 7d7a424a9f02f180a6313d90143854773cde056f Mon Sep 17 00:00:00 2001
From: Roland Conybeare <rconybeare@gmail.com>
Date: Tue, 7 May 2024 10:46:23 -0400
Subject: [PATCH] xo-unit: examples: + ex7

---
 example/CMakeLists.txt     |  1 +
 example/ex7/CMakeLists.txt | 14 ++++++++++++++
 example/ex7/ex7.cpp        | 32 ++++++++++++++++++++++++++++++++
 3 files changed, 47 insertions(+)
 create mode 100644 example/ex7/CMakeLists.txt
 create mode 100644 example/ex7/ex7.cpp

diff --git a/example/CMakeLists.txt b/example/CMakeLists.txt
index 86f0d7e6..fc69f5c4 100644
--- a/example/CMakeLists.txt
+++ b/example/CMakeLists.txt
@@ -4,3 +4,4 @@ add_subdirectory(ex3)
 add_subdirectory(ex4)
 add_subdirectory(ex5)
 add_subdirectory(ex6)
+add_subdirectory(ex7)
diff --git a/example/ex7/CMakeLists.txt b/example/ex7/CMakeLists.txt
new file mode 100644
index 00000000..33832b41
--- /dev/null
+++ b/example/ex7/CMakeLists.txt
@@ -0,0 +1,14 @@
+# xo-unit/example/ex7/CMakeLists.txt
+
+set(SELF_EXE xo_unit_ex7)
+set(SELF_SRCS ex7.cpp)
+
+xo_add_executable(${SELF_EXE} ${SELF_SRCS})
+
+# ----------------------------------------------------------------
+# dependencies..
+
+xo_self_headeronly_dependency(${SELF_EXE} xo_unit)
+xo_dependency(${SELF_EXE} xo_flatstring)
+
+# end CMakeLists.txt
diff --git a/example/ex7/ex7.cpp b/example/ex7/ex7.cpp
new file mode 100644
index 00000000..2339afa8
--- /dev/null
+++ b/example/ex7/ex7.cpp
@@ -0,0 +1,32 @@
+/** @file ex7.cpp **/
+
+#include "xo/unit/quantity.hpp"
+#include "xo/unit/quantity_iostream.hpp"
+#include <iostream>
+
+int
+main () {
+    //namespace u = xo::unit::units;
+    using namespace xo::qty;
+    //namespace su = xo::qty::su;
+    namespace q = xo::qty::qty;
+    using namespace std;
+
+    quantity qty1 = 7.55 * q::kilometer / q::minute / q::minute;
+    quantity qty2 = q::nanograms(123);
+    quantity qty3 = qty2 * qty1;
+
+    cerr << "qty1: " << qty1 << endl;
+    cerr << "qty2: " << qty2 << endl;
+    cerr << "qty3: " << qty3 << endl;
+
+    /* rescale to not-so-absurd units */
+
+    /* kg.m.s^-2 */
+    quantity res = qty3.rescale_ext<su::kilogram * su::meter / (su::second * su::second)>();
+
+    /* 2.57958e-10kg.m.s^-2 */
+    cerr << "res: " << res << endl;
+}
+
+/** end ex7.cpp */