mp-units/test/test_quantity.cpp

// 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/si/velocity.h"
#include <utility>

using namespace units;
using namespace units::literals;

namespace {

  template<typename T>
  class my_value {
    T data_{};

  public:
    my_value() = default;
    constexpr my_value(T v) : data_{v} {}
    constexpr operator T() const { return data_; }
  };

}  // namespace

namespace units {

  template<typename T>
  struct treat_as_floating_point<my_value<T>> : std::is_floating_point<T> {
  };

  template<typename T>
  struct quantity_values<my_value<T>> {
    static constexpr my_value<T> zero() { return my_value<T>(0); }
    static constexpr my_value<T> max() { return std::numeric_limits<T>::max(); }
    static constexpr my_value<T> min() { return std::numeric_limits<T>::lowest(); }
  };

}  // namespace units

namespace std {

  template<typename T, typename U>
  struct common_type<my_value<T>, U> : common_type<T, U> {
  };

  template<typename T, typename U>
  struct common_type<T, my_value<U>> : common_type<T, U> {
  };

}  // namespace std

namespace {

  using namespace units;
  using namespace units::literals;

  // class invariants

  //  constexpr quantity<meters<int>> error(0_m);  // should trigger a static_assert
  //  constexpr quantity<int, float> error(0);  // should trigger a static_assert
  //  constexpr quantity<int, std::ratio<-1, 1>> error(0);  // should trigger a static_assert

  // member types

  static_assert(std::is_same_v<meters<int>::rep, int>);
  static_assert(std::is_same_v<meters<float>::rep, float>);
  static_assert(std::is_same_v<meters<int>::ratio, std::ratio<1, 1>>);
  static_assert(std::is_same_v<kilometers<int>::ratio, std::ratio<1000, 1>>);

  // constructors

  static_assert(meters<int>().count() == 0);
  constexpr meters<int> kilometer{1000};
  static_assert(kilometer.count() == 1000);
  static_assert(meters<int>(kilometer).count() == kilometer.count());

  static_assert(meters<int>(1).count() == 1);
  static_assert(meters<int>(my_value<int>(1)).count() == 1);
  static_assert(meters<my_value<int>>(1).count() == 1);
  //  static_assert(meters<int>(1.0).count() == 1);   // should not compile
  //  static_assert(meters<int>(my_value<float>(1.0)).count() == 1); // should not compile
  //  static_assert(meters<my_value<int>>(1.0).count() == 1);   // should not compile
  static_assert(meters<float>(1.0).count() == 1.0);
  static_assert(meters<float>(my_value<float>(1.0)).count() == 1.0);
  static_assert(meters<float>(1).count() == 1.0);
  static_assert(meters<float>(my_value<int>(1)).count() == 1.0);
  static_assert(meters<float>(3.14f).count() == 3.14f);
  static_assert(meters<my_value<float>>(1.0).count() == 1.0);
  static_assert(meters<my_value<float>>(1).count() == 1.0);
  static_assert(meters<my_value<float>>(3.14f).count() == 3.14f);

  static_assert(meters<int>(kilometer).count() == 1000);
  //  static_assert(meters<int>(meters<float>(3.14)).count() == 3);   // should not compile
  static_assert(meters<int>(quantity_cast<meters<int>>(3.14_m)).count() == 3);
  //  static_assert(meters<int>(meters<my_value<float>>(1000.0)).count() == 1000);   // should not compile
  //  static_assert(meters<my_value<int>>(1000.0_m).count() == 1000);   // should not compile
  static_assert(meters<float>(1000.0_m).count() == 1000.0);
  static_assert(meters<float>(meters<my_value<float>>(1000.0)).count() == 1000.0);
  static_assert(meters<my_value<float>>(1000.0_m).count() == 1000.0);
  static_assert(meters<float>(kilometer).count() == 1000.0);
  static_assert(meters<my_value<float>>(kilometer).count() == 1000.0);
  static_assert(meters<int>(1_km).count() == 1000);
  //  static_assert(meters<int>(1_s).count() == 1);   // should not compile
  //  static_assert(kilometers<int>(1010_m).count() == 1);   // should not compile
  static_assert(kilometers<int>(quantity_cast<kilometers<int>>(1010_m)).count() == 1);

  // assignment operator

  static_assert([]() {
    meters<int> l1(1), l2(2);
    return l2 = l1;
  }()
                    .count() == 1);

  // static member functions

  static_assert(meters<int>::zero().count() == 0);
  static_assert(meters<int>::min().count() == std::numeric_limits<int>::lowest());
  static_assert(meters<int>::max().count() == std::numeric_limits<int>::max());
  static_assert(meters<float>::zero().count() == 0.0);
  static_assert(meters<float>::min().count() == std::numeric_limits<float>::lowest());
  static_assert(meters<float>::max().count() == std::numeric_limits<float>::max());
  static_assert(meters<my_value<int>>::zero().count() == 0);
  static_assert(meters<my_value<int>>::min().count() == std::numeric_limits<int>::lowest());
  static_assert(meters<my_value<int>>::max().count() == std::numeric_limits<int>::max());
  static_assert(meters<my_value<float>>::zero().count() == 0.0);
  static_assert(meters<my_value<float>>::min().count() == std::numeric_limits<float>::lowest());
  static_assert(meters<my_value<float>>::max().count() == std::numeric_limits<float>::max());

  // unary member operators

  static_assert((+kilometer).count() == 1000);
  static_assert((-kilometer).count() == -1000);
  static_assert((+(-kilometer)).count() == -1000);
  static_assert((-(-kilometer)).count() == 1000);

  // binary member operators

  static_assert([](auto v) {
    auto vv = v++;
    return std::make_pair(v, vv);
  }(kilometer) == std::make_pair(meters<int>(1001), meters<int>(1000)));
  static_assert([](auto v) {
    auto vv = ++v;
    return std::make_pair(v, vv);
  }(kilometer) == std::make_pair(meters<int>(1001), meters<int>(1001)));
  static_assert([](auto v) {
    auto vv = v--;
    return std::make_pair(v, vv);
  }(kilometer) == std::make_pair(meters<int>(999), meters<int>(1000)));
  static_assert([](auto v) {
    auto vv = --v;
    return std::make_pair(v, vv);
  }(kilometer) == std::make_pair(meters<int>(999), meters<int>(999)));

  // compound assignment

  static_assert((1_m += 1_m).count() == 2);
  static_assert((2_m -= 1_m).count() == 1);
  static_assert((1_m *= 2).count() == 2);
  static_assert((2_m /= 2).count() == 1);
  static_assert((7_m %= 2).count() == 1);
  static_assert((7_m %= 2_m).count() == 1);

  // non-member arithmetic operators

  static_assert(std::is_same_v<decltype(meters<int>() + meters<float>()), meters<float>>);
  static_assert(std::is_same_v<decltype(meters<float>() - meters<int>()), meters<float>>);
  static_assert(std::is_same_v<decltype(meters<int>() * 1.0f), meters<float>>);
  static_assert(std::is_same_v<decltype(1.0f * meters<int>()), meters<float>>);
  static_assert(std::is_same_v<decltype(meters<int>() / 1.0f), meters<float>>);
  static_assert(std::is_same_v<decltype(meters<int>() / meters<float>()), float>);
  static_assert(std::is_same_v<decltype(meters<int>() % short(1)), meters<int>>);
  static_assert(std::is_same_v<decltype(meters<int>() % meters<short>(1)), meters<int>>);

  static_assert((1_m + kilometer).count() == 1001);
  static_assert((1_m + 1_km).count() == 1001);
  static_assert((kilometer - 1_m).count() == 999);
  static_assert((1_km - 1_m).count() == 999);
  static_assert((2_m * 2).count() == 4);
  static_assert((3 * 3_m).count() == 9);
  static_assert((4_m / 2).count() == 2);
  static_assert(4_m / 2_m == 2);
  static_assert(4_km / 2000_m == 2);
  static_assert((7_m % 2).count() == 1);
  static_assert((7_m % 2_m).count() == 1);
  static_assert((7_km % 2000_m).count() == 1000);

  // comparators

  static_assert(2_m + 1_m == 3_m);
  static_assert(!(2_m + 2_m == 3_m));
  static_assert(2_m + 2_m != 3_m);
  static_assert(!(2_m + 2_m != 4_m));
  static_assert(2_m > 1_m);
  static_assert(!(1_m > 1_m));
  static_assert(1_m < 2_m);
  static_assert(!(2_m < 2_m));
  static_assert(2_m >= 1_m);
  static_assert(2_m >= 2_m);
  static_assert(!(2_m >= 3_m));
  static_assert(1_m <= 2_m);
  static_assert(2_m <= 2_m);
  static_assert(!(3_m <= 2_m));

  static_assert(3_m == 3.0_m);
  static_assert(3_m != 3.14_m);
  static_assert(2_m > 1.0_m);
  static_assert(1.0_m < 2_m);
  static_assert(2.0_m >= 1_m);
  static_assert(1_m <= 2.0_m);

  static_assert(1000_m == 1_km);
  static_assert(1001_m != 1_km);
  static_assert(1001_m > 1_km);
  static_assert(999_m < 1_km);
  static_assert(1000_m >= 1_km);
  static_assert(1000_m <= 1_km);

// is_quantity

  static_assert(units::detail::is_quantity<millimeters<int>>::value);

  // common_type

  static_assert(std::is_same_v<std::common_type_t<meters<int>, kilometers<int>>, meters<int>>);
  static_assert(std::is_same_v<std::common_type_t<kilometers<long long>, meters<int>>, meters<long long>>);
  static_assert(std::is_same_v<std::common_type_t<kilometers<long long>, millimeters<float>>, millimeters<float>>);

  // quantity_cast

  // static_assert(quantity_cast<int>(2_km).count() == 2000);  // should not compile
  static_assert(quantity_cast<meters<int>>(2_km).count() == 2000);
  static_assert(quantity_cast<kilometers<int>>(2000_m).count() == 2);

  // time

  //  static_assert(1_s == 1_m);  // should not compile
  static_assert(1_h == 3600_s);

  // length

  static_assert(1_km == 1000_m);
  static_assert(1_km + 1_m == 1001_m);
  static_assert(10_km / 5_km == 2);
  static_assert(10_km / 2 == 5_km);

  // velocity

  static_assert(10_m / 5_s == 2_mps);
  static_assert(10 / 5_s * 1_m == 2_mps);
  static_assert(1_km / 1_s == 1000_mps);
  static_assert(2_kmph * 2_h == 4_km);
  static_assert(2_km / 2_kmph == 1_h);

}  // namespace