From 8543ab65d19c7ed3d08573f012d14cb722536dda Mon Sep 17 00:00:00 2001
From: Mateusz Pusz <mateusz.pusz@gmail.com>
Date: Sat, 19 Oct 2019 20:51:20 +0200
Subject: [PATCH] pow<0> support added

---
 src/include/units/math.h             | 7 +++++++
 test/unit_test/runtime/math_test.cpp | 2 +-
 test/unit_test/static/math_test.cpp  | 1 +
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/include/units/math.h b/src/include/units/math.h
index f9e0d289..3dd70d92 100644
--- a/src/include/units/math.h
+++ b/src/include/units/math.h
@@ -27,6 +27,13 @@
 
 namespace units {
 
+  template<std::size_t N, typename U, typename Rep>
+    requires N == 0
+  inline Rep AUTO pow(const quantity<U, Rep>&) noexcept
+  {
+    return 1;
+  }
+
   template<std::size_t N, typename U, typename Rep>
   inline Quantity AUTO pow(const quantity<U, Rep>& q) noexcept
   {
diff --git a/test/unit_test/runtime/math_test.cpp b/test/unit_test/runtime/math_test.cpp
index 5491397b..4e72e26b 100644
--- a/test/unit_test/runtime/math_test.cpp
+++ b/test/unit_test/runtime/math_test.cpp
@@ -31,7 +31,7 @@ using namespace units;
 
 TEST_CASE("pow<N>() on quantity changes the value and the dimension accordingly", "[math][pow]")
 {
-  //  CHECK(pow<0>(2m) == 2);
+  CHECK(pow<0>(2m) == 1);
   CHECK(pow<1>(2m) == 2m);
   CHECK(pow<2>(2m) == 4sq_m);
   CHECK(pow<3>(2m) == 8cub_m);
diff --git a/test/unit_test/static/math_test.cpp b/test/unit_test/static/math_test.cpp
index 907a3da1..09a4759c 100644
--- a/test/unit_test/static/math_test.cpp
+++ b/test/unit_test/static/math_test.cpp
@@ -27,6 +27,7 @@ using namespace units;
 
 namespace {
 
+  static_assert(std::is_same_v<decltype(pow<0>(2m)), std::int64_t>);
   static_assert(std::is_same_v<decltype(pow<1>(2m)), decltype(2m)>);
   static_assert(std::is_same_v<decltype(pow<2>(2m)), decltype(4sq_m)>);
   static_assert(std::is_same_v<decltype(sqrt(4sq_m)), decltype(2m)>);