mp-units/example/hello_units.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/concepts.h>
#include <units/dimension.h>

namespace units::isq {

inline constexpr struct dim_length : base_dimension<"L"> {
} dim_length;

// template<typename T>
// concept Length = QuantityOf<T, dim_length>;

inline constexpr struct dim_time : base_dimension<"T"> {
} dim_time;
inline constexpr struct dim_frequency : decltype(1 / dim_time) {
} dim_frequency;
inline constexpr struct dim_area : decltype(dim_length * dim_length) {
} dim_area;
inline constexpr struct dim_volume : decltype(dim_area * dim_length) {
} dim_volume;
inline constexpr struct dim_speed : decltype(dim_length / dim_time) {
} dim_speed;
inline constexpr struct dim_acceleration : decltype(dim_speed / dim_time) {
} dim_acceleration;

// inline constexpr auto speed = length / time;

}  // namespace units::isq

#include <units/isq/si/prefixes.h>
#include <units/unit.h>

namespace units {

namespace isq::si {

// length units
inline constexpr struct metre : named_unit<"m"> {
} metre;
inline constexpr struct kilometre : kilo<metre> {
} kilometre;

inline constexpr struct astronomical_unit : named_scaled_unit<"au", mag<149'597'870'700>(), metre> {
} astronomical_unit;

// area units
inline constexpr struct square_metre : derived_unit<decltype(metre * metre)> {
} square_metre;

// volume units
inline constexpr struct cubic_metre : derived_unit<decltype(square_metre * metre)> {
} cubic_metre;

// time units
inline constexpr struct second : named_unit<"s"> {
} second;
inline constexpr struct minute : named_scaled_unit<"min", mag<60>(), second> {
} minute;
inline constexpr struct hour : named_scaled_unit<"h", mag<60>(), minute> {
} hour;
inline constexpr struct day : named_scaled_unit<"d", mag<24>(), hour> {
} day;

// not a time unit!
inline constexpr struct second_squared : derived_unit<decltype(second * second)> {
} second_squared;

// mass units
inline constexpr struct gram : named_unit<"g"> {
} gram;
inline constexpr struct kilogram : kilo<gram> {
} kilogram;
inline constexpr struct tonne : named_scaled_unit<"t", mag<1000>(), gram> {
} tonne;

// other units
inline constexpr struct hertz : named_unit<"Hz", 1 / second> {
} hertz;
inline constexpr struct newton : named_unit<"N", kilogram * metre / second_squared> {
} newton;
inline constexpr struct pascal : named_unit<"Pa", kilogram / (metre * second_squared)> {
} pascal;
inline constexpr struct joule : named_unit<"J", newton * metre> {
} joule;
inline constexpr struct watt : named_unit<"W", joule / second> {
} watt;

namespace short_units {

// TODO collide with reference names
// inline namespace length {

inline constexpr auto m = metre;
inline constexpr auto km = kilometre;
inline constexpr auto au = astronomical_unit;

// }  // namespace length

// inline namespace area {

inline constexpr auto m2 = square_metre;

// }

// inline namespace volume {

inline constexpr auto m3 = cubic_metre;

// }

// inline namespace time {

inline constexpr auto s = second;
inline constexpr auto min = minute;
inline constexpr auto h = hour;
inline constexpr auto d = day;

inline constexpr auto s2 = second_squared;

// }  // namespace time

// inline namespace mass {

inline constexpr auto g = gram;
inline constexpr auto kg = kilogram;
inline constexpr auto t = tonne;

// }  // namespace mass

// inline namespace frequency {

inline constexpr auto Hz = hertz;

// }

// inline namespace force {

inline constexpr auto N = newton;

// }

// inline namespace pressure {

inline constexpr auto Pa = pascal;

// }

// inline namespace energy {

inline constexpr auto J = joule;

// }

// inline namespace power {

inline constexpr auto W = watt;

// }

}  // namespace short_units

}  // namespace isq::si
}  // namespace units

#include <units/system_reference.h>

namespace units::isq::si {

inline constexpr struct length : system_reference<length, dim_length, metre> {
} length;
inline constexpr struct time : system_reference<time, dim_time, second> {
} time;
inline constexpr struct frequency : system_reference<frequency, dim_frequency, hertz> {
} frequency;
inline constexpr struct area : system_reference<area, dim_area, square_metre> {
} area;
inline constexpr struct volume : system_reference<volume, dim_volume, cubic_metre> {
} volume;
inline constexpr struct speed : system_reference<speed, dim_speed, metre / second> {
} speed;
inline constexpr struct acceleration : system_reference<acceleration, dim_acceleration, metre / second / second> {
} acceleration;

}  // namespace units::isq::si


template<auto V, typename T>
inline constexpr bool is_of_type = std::is_same_v<std::remove_cvref_t<decltype(V)>, T>;

namespace units::isq {

// derived dimension expression template syntax verification
static_assert(is_of_type<1 / dim_time, derived_dimension<struct dim_one, per<struct dim_time>>>);
static_assert(is_of_type<1 / (1 / dim_time), struct dim_time>);

static_assert(is_of_type<dim_one * dim_time, struct dim_time>);
static_assert(is_of_type<dim_time * dim_one, struct dim_time>);
static_assert(is_of_type<dim_one * (1 / dim_time), derived_dimension<struct dim_one, per<struct dim_time>>>);
static_assert(is_of_type<1 / dim_time * dim_one, derived_dimension<struct dim_one, per<struct dim_time>>>);

static_assert(is_of_type<dim_length * dim_time, derived_dimension<struct dim_length, struct dim_time>>);
static_assert(is_of_type<dim_length * dim_length, derived_dimension<power<struct dim_length, 2>>>);

static_assert(
  is_of_type<dim_length * dim_length * dim_time, derived_dimension<power<struct dim_length, 2>, struct dim_time>>);
static_assert(
  is_of_type<dim_length * dim_time * dim_length, derived_dimension<power<struct dim_length, 2>, struct dim_time>>);

static_assert(
  is_of_type<dim_length*(dim_time* dim_length), derived_dimension<power<struct dim_length, 2>, struct dim_time>>);
static_assert(
  is_of_type<dim_time*(dim_length* dim_length), derived_dimension<power<struct dim_length, 2>, struct dim_time>>);

static_assert(is_of_type<1 / dim_time * dim_length, derived_dimension<struct dim_length, per<struct dim_time>>>);
static_assert(is_of_type<1 / dim_time * dim_time, struct dim_one>);

static_assert(is_of_type<dim_time / dim_one, struct dim_time>);
static_assert(is_of_type<1 / dim_time / dim_one, derived_dimension<struct dim_one, per<struct dim_time>>>);

static_assert(is_of_type<dim_length / dim_time * dim_time, struct dim_length>);
static_assert(
  is_of_type<1 / dim_time * (1 / dim_time), derived_dimension<struct dim_one, per<power<struct dim_time, 2>>>>);
static_assert(is_of_type<1 / (dim_time * dim_time), derived_dimension<struct dim_one, per<power<struct dim_time, 2>>>>);
static_assert(is_of_type<1 / (1 / (dim_time * dim_time)), derived_dimension<power<struct dim_time, 2>>>);

static_assert(is_of_type<dim_length / dim_time * (1 / dim_time),
                         derived_dimension<struct dim_length, per<power<struct dim_time, 2>>>>);
static_assert(is_of_type<dim_length / dim_time*(dim_length / dim_time),
                         derived_dimension<power<struct dim_length, 2>, per<power<struct dim_time, 2>>>>);
static_assert(is_of_type<dim_length / dim_time*(dim_time / dim_length), struct dim_one>);

static_assert(
  is_of_type<dim_speed / dim_acceleration, derived_dimension<struct dim_speed, per<struct dim_acceleration>>>);
static_assert(
  is_of_type<dim_acceleration / dim_speed, derived_dimension<struct dim_acceleration, per<struct dim_speed>>>);
static_assert(is_of_type<dim_speed * dim_speed / dim_length,
                         derived_dimension<power<struct dim_speed, 2>, per<struct dim_length>>>);
static_assert(is_of_type<1 / (dim_speed * dim_speed) * dim_length,
                         derived_dimension<struct dim_length, per<power<struct dim_speed, 2>>>>);

// comparisons of equivalent dimensions
static_assert(dim_length / dim_length == dim_one);

static_assert(1 / dim_time == dim_frequency);
static_assert(1 / dim_frequency == dim_time);
static_assert(dim_frequency * dim_time == dim_one);

static_assert(dim_length * dim_length == dim_area);
static_assert(dim_length * dim_length != dim_volume);
static_assert(dim_area / dim_length == dim_length);

static_assert(dim_length * dim_length * dim_length == dim_volume);
static_assert(dim_area * dim_length == dim_volume);
static_assert(dim_volume / dim_length == dim_area);
static_assert(dim_volume / dim_length / dim_length == dim_length);
static_assert(dim_area * dim_area / dim_length == dim_volume);
static_assert(dim_area * (dim_area / dim_length) == dim_volume);
static_assert(dim_volume / (dim_length * dim_length) == dim_length);

static_assert(dim_length / dim_time == dim_speed);
static_assert(dim_length * dim_time != dim_speed);
static_assert(dim_length / dim_time / dim_time != dim_speed);
static_assert(dim_length / dim_speed == dim_time);
static_assert(dim_speed * dim_time == dim_length);

static_assert(dim_length / dim_time / dim_time == dim_acceleration);
static_assert(dim_length / (dim_time * dim_time) == dim_acceleration);
static_assert(dim_speed / dim_time == dim_acceleration);
static_assert(dim_speed / dim_acceleration == dim_time);
static_assert(dim_acceleration * dim_time == dim_speed);
static_assert(dim_acceleration * (dim_time * dim_time) == dim_length);
static_assert(dim_acceleration / dim_speed == dim_frequency);

}  // namespace units::isq


namespace units::isq::si {

// derived unit expression template syntax verification
static_assert(is_of_type<1 / second, derived_unit<struct one, per<struct second>>>);
static_assert(is_of_type<1 / (1 / second), struct second>);

static_assert(is_of_type<one * second, struct second>);
static_assert(is_of_type<second * one, struct second>);
static_assert(is_of_type<one * (1 / second), derived_unit<struct one, per<struct second>>>);
static_assert(is_of_type<1 / second * one, derived_unit<struct one, per<struct second>>>);

static_assert(is_of_type<metre * second, derived_unit<struct metre, struct second>>);
static_assert(is_of_type<metre * metre, derived_unit<power<struct metre, 2>>>);

static_assert(is_of_type<metre * metre * second, derived_unit<power<struct metre, 2>, struct second>>);
static_assert(is_of_type<metre * second * metre, derived_unit<power<struct metre, 2>, struct second>>);

static_assert(is_of_type<metre*(second* metre), derived_unit<power<struct metre, 2>, struct second>>);
static_assert(is_of_type<second*(metre* metre), derived_unit<power<struct metre, 2>, struct second>>);

static_assert(is_of_type<1 / second * metre, derived_unit<struct metre, per<struct second>>>);
static_assert(is_of_type<1 / second * second, struct one>);

static_assert(is_of_type<second / one, struct second>);
static_assert(is_of_type<1 / second / one, derived_unit<struct one, per<struct second>>>);

static_assert(is_of_type<metre / second * second, struct metre>);
static_assert(is_of_type<1 / second * (1 / second), derived_unit<struct one, per<power<struct second, 2>>>>);
static_assert(is_of_type<1 / (second * second), derived_unit<struct one, per<power<struct second, 2>>>>);
static_assert(is_of_type<1 / (1 / (second * second)), derived_unit<power<struct second, 2>>>);

static_assert(is_of_type<metre / second * (1 / second), derived_unit<struct metre, per<power<struct second, 2>>>>);
static_assert(
  is_of_type<metre / second*(metre / second), derived_unit<power<struct metre, 2>, per<power<struct second, 2>>>>);
static_assert(is_of_type<metre / second*(second / metre), struct one>);

static_assert(is_of_type<watt / joule, derived_unit<struct watt, per<struct joule>>>);
static_assert(is_of_type<joule / watt, derived_unit<struct joule, per<struct watt>>>);

// comparisons of equivalent dimensions
// static_assert(metre / metre == one);

// static_assert(1 / second == dim_frequency);
// static_assert(1 / dim_frequency == second);
// static_assert(dim_frequency * second == one);

// static_assert(metre * metre == dim_area);
// static_assert(metre * metre != dim_volume);
// static_assert(dim_area / metre == metre);

// static_assert(metre * metre * metre == dim_volume);
// static_assert(dim_area * metre == dim_volume);
// static_assert(dim_volume / metre == dim_area);
// static_assert(dim_volume / metre / metre == metre);
// static_assert(dim_area * dim_area / metre == dim_volume);
// static_assert(dim_area * (dim_area / metre) == dim_volume);
// static_assert(dim_volume / (metre * metre) == metre);

// static_assert(metre / second == dim_speed);
// static_assert(metre * second != dim_speed);
// static_assert(metre / second / second != dim_speed);
// static_assert(metre / dim_speed == second);
// static_assert(dim_speed * second == metre);

// static_assert(metre / second / second == dim_acceleration);
// static_assert(metre / (second * second) == dim_acceleration);
// static_assert(dim_speed / second == dim_acceleration);
// static_assert(dim_speed / dim_acceleration == second);
// static_assert(dim_acceleration * second == dim_speed);
// static_assert(dim_acceleration * (second * second) == metre);
// static_assert(dim_acceleration / dim_speed == dim_frequency);


// Bq + Hz should not compile

// Bq + Hz + 1/s should compile?


}  // namespace units::isq::si


using namespace units;
using namespace units::isq::si;
using namespace units::isq::si::short_units;

/* Frequency */ auto freq1 = 20 * frequency[Hz];
// /* Frequency */ auto freq2 = 20 / (1 * time[s]);
quantity<frequency[Hz]> freq3(20);
// quantity<frequency[1 / s]> freq4(20);
// quantity<1 / time[s]> freq5(20);


/* Speed */ auto speed1 = 20 * speed[m / s];
/* Speed */ auto speed2 = 20 * (length[m] / isq::si::time[s]);
// quantity<speed[m / s]> speed3(20);
// quantity<length[m] / time[s]> speed4(20);


// quantity<kilo<metre> / second> speed1(123);
// quantity<km / s> speed2(123);
// auto speed3 = 123 * (kilo<metre> / second);
// auto speed4 = 123 * (km / s);

template<typename T>
void print();

// constexpr auto avg_speed(quantity<length[km]> d, quantity<isq::si::time[h]> t) { return d / t; }

int main()
{
  print<decltype(speed1)>();
  print<decltype(speed2)>();
}