From 6539b492a34b3359ef14962c3b3c2192c2db77ef Mon Sep 17 00:00:00 2001
From: Mateusz Pusz <mateusz.pusz@gmail.com>
Date: Mon, 4 Jan 2021 13:05:26 +0100
Subject: [PATCH] fix: `std::chrono::duration` support fixed

Resolves #198
---
 src/include/units/quantity.h          |  8 ++++----
 test/unit_test/static/chrono_test.cpp | 13 +++++++++++--
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/src/include/units/quantity.h b/src/include/units/quantity.h
index 142cf80b..a3b91944 100644
--- a/src/include/units/quantity.h
+++ b/src/include/units/quantity.h
@@ -136,13 +136,13 @@ public:
   explicit(!(is_same_v<dimension, dim_one> && is_same_v<unit, ::units::one>))
   constexpr quantity(const Value& v) : value_(static_cast<rep>(v)) {}
 
-  template<QuantityLike Q>
-    requires std::same_as<quantity, quantity_like_type<Q>>
-  explicit constexpr quantity(const Q& q) : value_(q.count()) {}
-
   template<safe_castable_to_<quantity> Q>
   constexpr quantity(const Q& q) : value_(quantity_cast<quantity>(q).count()) {}
 
+  template<QuantityLike Q>
+    requires safe_castable_to_<quantity_like_type<Q>, quantity>
+  explicit constexpr quantity(const Q& q) : quantity(quantity_like_type<Q>(quantity_like_traits<Q>::count(q))) {}
+
   quantity& operator=(const quantity&) = default;
   quantity& operator=(quantity&&) = default;
 
diff --git a/test/unit_test/static/chrono_test.cpp b/test/unit_test/static/chrono_test.cpp
index 7186300b..75fd86f6 100644
--- a/test/unit_test/static/chrono_test.cpp
+++ b/test/unit_test/static/chrono_test.cpp
@@ -32,16 +32,25 @@ using namespace units::physical::si::literals;
 using namespace std::chrono_literals;
 
 
-// construction
+// construction - same rep type
 static_assert(std::constructible_from<si::time<si::second, std::chrono::seconds::rep>, std::chrono::seconds>);
 static_assert(!std::convertible_to<std::chrono::seconds, si::time<si::second, std::chrono::seconds::rep>>);
 static_assert(std::constructible_from<si::time<si::hour, std::chrono::hours::rep>, std::chrono::hours>);
 static_assert(!std::convertible_to<std::chrono::hours, si::time<si::hour, std::chrono::hours::rep>>);
-static_assert(!std::constructible_from<si::time<si::second, std::chrono::hours::rep>, std::chrono::hours>);
+static_assert(std::constructible_from<si::time<si::second, std::chrono::hours::rep>, std::chrono::hours>);
 static_assert(!std::convertible_to<std::chrono::hours, si::time<si::second, std::chrono::hours::rep>>);
 static_assert(!std::constructible_from<si::time<si::hour, std::chrono::seconds::rep>, std::chrono::seconds>);
 static_assert(!std::convertible_to<std::chrono::seconds, si::time<si::hour, std::chrono::seconds::rep>>);
 
+// construction - different rep type (integral to a floating-point)
+static_assert(std::constructible_from<si::time<si::second>, std::chrono::seconds>);
+static_assert(!std::convertible_to<std::chrono::seconds, si::time<si::second>>);
+static_assert(std::constructible_from<si::time<si::second>, std::chrono::hours>);
+static_assert(!std::convertible_to<std::chrono::hours, si::time<si::second>>);
+static_assert(std::constructible_from<si::time<si::hour>, std::chrono::seconds>);
+static_assert(!std::convertible_to<std::chrono::seconds, si::time<si::hour>>);
+
+
 // CTAD
 static_assert(is_same_v<decltype(quantity{1s}), si::time<si::second, std::chrono::seconds::rep>>);
 static_assert(is_same_v<decltype(quantity{1h}), si::time<si::hour, std::chrono::hours::rep>>);