text: // 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.
  
  #include "units/quantity_point.h"
  #include "test_tools.h"
  #include "units/math.h"
  #include "units/physical/si/si.h"
  #include "units/physical/si/us/us.h"
  #include <chrono>
  #include <utility>
  
  namespace {
  
  using namespace units;
  using namespace units::physical::si;
  
  // class invariants
  
  template<typename DimLength>
  concept invalid_types = requires
  {
    !requires { typename quantity_point<DimLength, second, int>; };  // unit of a different dimension
    !requires { typename quantity_point<DimLength, metre, quantity<DimLength, metre, int>>; };  // quantity used as Rep
    // quantity point used as Rep
    !requires { typename quantity_point<DimLength, metre, quantity_point<DimLength, metre, int>>; };
    !requires { typename quantity<metre, DimLength, double>; };  // reordered arguments
  };
  
  static_assert(invalid_types<dim_length>);
  
  // member types
  
  static_assert(is_same_v<quantity_point<dim_length, metre, int>::rep, int>);
  static_assert(is_same_v<quantity_point<dim_length, metre, double>::rep, double>);
  static_assert(is_same_v<quantity_point<dim_length, metre, int>::unit, metre>);
  static_assert(is_same_v<quantity_point<dim_length, kilometre, int>::unit, kilometre>);
  
  // constructors
  
  static_assert(quantity_point<dim_length, metre, int>().relative() == 0_q_m);
  constexpr quantity_point<dim_length, metre, int> km{1000_q_m};
  static_assert(km.relative() == 1000_q_m);
  static_assert(quantity_point<dim_length, metre, int>(km).relative() == km.relative());
  
  static_assert(quantity_point<dim_length, metre, int>(1_q_m).relative() == 1_q_m);
  static_assert(!std::is_constructible_v<quantity_point<dim_length, metre, int>, double>); // truncating conversion
  static_assert(quantity_point<dim_length, metre, double>(1.0_q_m).relative() == 1.0_q_m);
  static_assert(quantity_point<dim_length, metre, double>(1_q_m).relative() == 1_q_m);
  static_assert(quantity_point<dim_length, metre, long double>(3.14_q_m).relative() == 3.14_q_m);
  
  static_assert(quantity_point<dim_length, metre, int>(km).relative() == 1000_q_m);
  static_assert(!std::is_constructible_v<quantity_point<dim_length, metre, int>,
                                         quantity_point<dim_length, metre, double>>);  // truncating conversion
  static_assert(quantity_point<dim_length, metre, double>(quantity_point(1000.0_q_m)).relative() == 1000.0_q_m);
  static_assert(quantity_point<dim_length, metre, double>(km).relative() == 1000.0_q_m);
  static_assert(quantity_point<dim_length, metre, int>(quantity_point(1_q_km)).relative() == 1000_q_m);
  static_assert(!std::is_constructible_v<quantity_point<dim_length, metre, int>,
                                         quantity_point<dim_time, second, int>>);  // different dimensions
  static_assert(!std::is_constructible_v<quantity_point<dim_length, kilometre, int>,
                                         quantity_point<dim_length, metre, int>>);  // truncating conversion
  
  // assignment operator
  
  static_assert([]() { quantity_point<dim_length, metre, int> l1(1_q_m), l2{}; return l2 = l1; }().relative() == 1_q_m);
  
  // static member functions
  
  static_assert(quantity_point<dim_length, metre, int>::min().relative().count() == std::numeric_limits<int>::lowest());
  static_assert(quantity_point<dim_length, metre, int>::max().relative().count() == std::numeric_limits<int>::max());
  static_assert(quantity_point<dim_length, metre, double>::min().relative().count() ==
                std::numeric_limits<double>::lowest());
  static_assert(quantity_point<dim_length, metre, double>::max().relative().count() ==
                std::numeric_limits<double>::max());
  
  // unary member operators
  
  static_assert([](auto v) {
    auto vv = v++;
    return std::pair(v, vv);
  }(km) == std::pair(quantity_point<dim_length, metre, int>(1001_q_m), quantity_point<dim_length, metre, int>(1000_q_m)));
  static_assert([](auto v) {
    auto vv = ++v;
    return std::pair(v, vv);
  }(km) == std::pair(quantity_point<dim_length, metre, int>(1001_q_m), quantity_point<dim_length, metre, int>(1001_q_m)));
  static_assert([](auto v) {
    auto vv = v--;
    return std::pair(v, vv);
  }(km) == std::pair(quantity_point<dim_length, metre, int>(999_q_m), quantity_point<dim_length, metre, int>(1000_q_m)));
  static_assert([](auto v) {
    auto vv = --v;
    return std::pair(v, vv);
  }(km) == std::pair(quantity_point<dim_length, metre, int>(999_q_m), quantity_point<dim_length, metre, int>(999_q_m)));
  
  // compound assignment
  
  static_assert((quantity_point(1_q_m) += 1_q_m).relative().count() == 2);
  static_assert((quantity_point(2_q_m) -= 1_q_m).relative().count() == 1);
  
  // non-member arithmetic operators
  
  static_assert(compare<decltype(quantity_point<dim_length, metre, int>() + length<metre, double>()),
                               quantity_point<dim_length, metre, double>>);
  static_assert(compare<decltype(length<metre, int>() + quantity_point<dim_length, metre, double>()),
                               quantity_point<dim_length, metre, double>>);
  static_assert(compare<decltype(quantity_point<dim_length, kilometre, int>() + length<metre, double>()),
                               quantity_point<dim_length, metre, double>>);
  static_assert(compare<decltype(length<kilometre, int>() + quantity_point<dim_length, metre, double>()),
                               quantity_point<dim_length, metre, double>>);
  static_assert(compare<decltype(quantity_point<dim_length, metre, double>() - length<metre, int>()),
                               quantity_point<dim_length, metre, double>>);
  static_assert(compare<decltype(quantity_point<dim_length, kilometre, double>() - length<metre, int>()),
                               quantity_point<dim_length, metre, double>>);
  static_assert(
      compare<decltype(quantity_point<dim_length, metre, double>() - quantity_point<dim_length, metre, int>()),
                     length<metre, double>>);
  static_assert(
      compare<decltype(quantity_point<dim_length, kilometre, double>() - quantity_point<dim_length, metre, int>()),
                     length<metre, double>>);
  
  static_assert((1_q_m + km).relative().count() == 1001);
  static_assert((quantity_point(1_q_m) + 1_q_km).relative().count() == 1001);
  static_assert((km - 1_q_m).relative().count() == 999);
  static_assert((quantity_point(1_q_km) - quantity_point(1_q_m)).count() == 999);
  
  // comparators
  
  static_assert(quantity_point(2_q_m) + 1_q_m == quantity_point(3_q_m));
  static_assert(!(2_q_m + quantity_point(2_q_m) == quantity_point(3_q_m)));
  static_assert(quantity_point(2_q_m) + 2_q_m != quantity_point(3_q_m));
  static_assert(!(2_q_m + quantity_point(2_q_m) != quantity_point(4_q_m)));
  static_assert(quantity_point(2_q_m) > quantity_point(1_q_m));
  static_assert(!(quantity_point(1_q_m) > quantity_point(1_q_m)));
  static_assert(quantity_point(1_q_m) < quantity_point(2_q_m));
  static_assert(!(quantity_point(2_q_m) < quantity_point(2_q_m)));
  static_assert(quantity_point(2_q_m) >= quantity_point(1_q_m));
  static_assert(quantity_point(2_q_m) >= quantity_point(2_q_m));
  static_assert(!(quantity_point(2_q_m) >= quantity_point(3_q_m)));
  static_assert(quantity_point(1_q_m) <= quantity_point(2_q_m));
  static_assert(quantity_point(2_q_m) <= quantity_point(2_q_m));
  static_assert(!(quantity_point(3_q_m) <= quantity_point(2_q_m)));
  
  static_assert(quantity_point(3_q_m) == quantity_point(3.0_q_m));
  static_assert(quantity_point(3_q_m) != quantity_point(3.14_q_m));
  static_assert(quantity_point(2_q_m) > quantity_point(1.0_q_m));
  static_assert(quantity_point(1.0_q_m) < quantity_point(2_q_m));
  static_assert(quantity_point(2.0_q_m) >= quantity_point(1_q_m));
  static_assert(quantity_point(1_q_m) <= quantity_point(2.0_q_m));
  
  static_assert(quantity_point(1000_q_m) == quantity_point(1_q_km));
  static_assert(quantity_point(1001_q_m) != quantity_point(1_q_km));
  static_assert(quantity_point(1001_q_m) > quantity_point(1_q_km));
  static_assert(quantity_point(999_q_m) < quantity_point(1_q_km));
  static_assert(quantity_point(1000_q_m) >= quantity_point(1_q_km));
  static_assert(quantity_point(1000_q_m) <= quantity_point(1_q_km));
  
  // alias units
  
  static_assert(quantity_point(2_q_l) + 2_q_ml == quantity_point(2002_q_ml));
  static_assert(2_q_l + quantity_point(2_q_ml) == quantity_point(2002_q_cm3));
  static_assert(quantity_point(2_q_l) + 2_q_cm3 == quantity_point(2002_q_ml));
  static_assert(2_q_dm3 + quantity_point(2_q_cm3) == quantity_point(2002_q_ml));
  
  // is_quantity_point
  
  static_assert(QuantityPoint<quantity_point<dim_length, millimetre, int>>);
  
  // common_quantity_point
  
  static_assert(compare<
                common_quantity_point<quantity_point<dim_length, metre, int>, quantity_point<dim_length, kilometre, int>>,
                quantity_point<dim_length, metre, int>>);
  static_assert(compare<common_quantity_point<quantity_point<dim_length, kilometre, long long>,
                                                     quantity_point<dim_length, metre, int>>,
                               quantity_point<dim_length, metre, long long>>);
  static_assert(compare<common_quantity_point<quantity_point<dim_length, kilometre, long long>,
                                                     quantity_point<dim_length, millimetre, double>>,
                               quantity_point<dim_length, millimetre, double>>);
  
  // common_type
  
  using namespace units::physical::si::us::literals;
  
  static_assert(std::equality_comparable<decltype(quantity_point(1_q_m))>);
  static_assert(std::equality_comparable_with<decltype(quantity_point(1_q_m)), decltype(quantity_point(1_q_km))>);
  static_assert(quantity_point(0_q_m) == quantity_point(0_q_ft_us));
  static_assert(std::equality_comparable_with<decltype(quantity_point(1_q_m)), decltype(quantity_point(1_q_ft_us))>);
  
  // quantity_cast
  
  static_assert(compare<decltype(quantity_point_cast<scaled_unit<ratio(1), metre>>(quantity_point(2_q_km)))::unit, metre>);
  
  static_assert(quantity_point_cast<quantity_point<dim_length, metre, int>>(quantity_point(2_q_km)).relative().count() ==
                2000);
  static_assert(
      quantity_point_cast<quantity_point<dim_length, kilometre, int>>(quantity_point(2000_q_m)).relative().count() == 2);
  static_assert(quantity_point_cast<quantity_point<dim_length, metre, int>>(quantity_point(1.23_q_m)).relative().count() ==
                1);
  static_assert(quantity_point_cast<length<metre, int>>(quantity_point(2_q_km)).relative().count() == 2000);
  static_assert(quantity_point_cast<length<kilometre, int>>(quantity_point(2000_q_m)).relative().count() == 2);
  static_assert(quantity_point_cast<length<metre, int>>(quantity_point(1.23_q_m)).relative().count() == 1);
  static_assert(quantity_point_cast<metre>(quantity_point(2_q_km)).relative().count() == 2000);
  static_assert(quantity_point_cast<kilometre>(quantity_point(2000_q_m)).relative().count() == 2);
  static_assert(quantity_point_cast<int>(quantity_point(1.23_q_m)).relative().count() == 1);
  static_assert(quantity_point_cast<dim_speed, kilometre_per_hour>(quantity_point(2000.0_q_m / 3600.0_q_s)).relative().count() == 2);
  
  // time
  
  static_assert(quantity_point{1_q_h} == quantity_point{3600_q_s});
  
  template<typename Metre>
  concept no_crossdimensional_equality = !requires
  {
      quantity_point(1_q_s) == quantity_point(length<Metre, int>(1));
  };
  
  static_assert(no_crossdimensional_equality<metre>);
  
  // length
  
  static_assert(quantity_point(1_q_km) != quantity_point(1_q_m));
  static_assert(quantity_point(1_q_km) == quantity_point(1000_q_m));
  static_assert(quantity_point(1_q_km) + 1_q_m == quantity_point(1001_q_m));
  static_assert(1_q_km + quantity_point(1_q_m) == quantity_point(1001_q_m));
  
  template<class T>
  concept dimensional_analysis = requires(T t)
  {
    pow<2>(t);
  };
  
  static_assert(!dimensional_analysis<quantity_point<dim_length, metre, int>>);
  
  }  // namespace
  