Area support added

src/include/units/area.h

@@ -0,0 +1,73 @@
+// The MIT License (MIT)
+//
+// Copyright (c) 2018 Mateusz Pusz
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+#pragma once
+
+#include <units/length.h>
+
+namespace units {
+
+  struct dimension_area : make_dimension_t<exp<base_dim_length, 2>> {};
+  template<> struct upcasting_traits<upcast_from<dimension_area>> : upcast_to<dimension_area> {};
+
+  template<typename T>
+  concept bool Area = Quantity<T> && std::experimental::ranges::Same<typename T::dimension, dimension_area>;
+
+  template<Unit U = struct square_meter, Number Rep = double>
+  using area = quantity<dimension_area, U, Rep>;
+
+  struct square_millimeter : derived_unit<dimension_area, millimeter> {};
+  template<> struct upcasting_traits<upcast_from<square_millimeter>> : upcast_to<square_millimeter> {};
+
+  struct square_centimeter : derived_unit<dimension_area, centimeter> {};
+  template<> struct upcasting_traits<upcast_from<square_centimeter>> : upcast_to<square_centimeter> {};
+
+  struct square_meter : derived_unit<dimension_area, meter> {};
+  template<> struct upcasting_traits<upcast_from<square_meter>> : upcast_to<square_meter> {};
+
+  struct square_kilometer : derived_unit<dimension_area, kilometer, meter> {};
+  template<> struct upcasting_traits<upcast_from<square_kilometer>> : upcast_to<square_kilometer> {};
+
+  struct square_foot : derived_unit<dimension_area, foot> {};
+  template<> struct upcasting_traits<upcast_from<square_foot>> : upcast_to<square_foot> {};
+
+  inline namespace literals {
+
+    // sq_mm
+    constexpr auto operator""_sq_mm(unsigned long long l) { return area<square_millimeter, std::int64_t>(l); }
+    constexpr auto operator""_sq_mm(long double l) { return area<square_millimeter, long double>(l); }
+
+    // sq_cm
+    constexpr auto operator""_sq_cm(unsigned long long l) { return area<square_centimeter, std::int64_t>(l); }
+    constexpr auto operator""_sq_cm(long double l) { return area<square_centimeter, long double>(l); }
+
+    // sq_m
+    constexpr auto operator""_sq_m(unsigned long long l) { return area<square_meter, std::int64_t>(l); }
+    constexpr auto operator""_sq_m(long double l) { return area<square_meter, long double>(l); }
+
+    // sq_km
+    constexpr auto operator""_sq_km(unsigned long long l) { return area<square_kilometer, std::int64_t>(l); }
+    constexpr auto operator""_sq_km(long double l) { return area<square_kilometer, long double>(l); }
+
+  }  // namespace literals
+
+}  // namespace units

test/test_units.cpp

@@ -31,6 +31,7 @@
 
 #include <units/frequency.h>
 #include <units/velocity.h>
+#include <units/area.h>
 
 #include <utility>
 
@@ -93,4 +94,10 @@ namespace {
   // static_assert(2000_m / 2_kmph == 1_h); // should not compile
   static_assert(quantity_cast<length<kilometer, int>>(2000_m) / 2_kmph == 1_h);
 
+  // area
+
+  static_assert(1_m * 1_m == 1_sq_m);
+  static_assert(10_km * 10_km == 100_sq_km);
+  static_assert(1_sq_m == 10'000_sq_cm);
+
 }  // namespace