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mp-units/src/include/units/quantity.h
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// 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/unit.h>
#include <units/bits/concepts.h>
#include <limits>
namespace std::experimental::units {
// is_quantity
namespace detail {
template<typename T>
inline constexpr bool is_quantity = false;
// partial specialization below after the first quantity forward declaration
}
template<typename T>
concept bool Quantity = detail::is_quantity<T>;
template<typename T, typename D>
concept bool QuantityOf = Quantity<T> && Dimension<D> && std::same_as<typename T::dimension, D>;
// Scalar
template<typename T>
concept bool Scalar = Number<T> && !Quantity<T>;
template<Unit U, Scalar Rep>
class quantity;
namespace detail {
template<typename U, typename Rep>
inline constexpr bool is_quantity<quantity<U, Rep>> = true;
} // namespace detail
// common_quantity
template<Quantity Q1, Quantity Q2, Scalar Rep>
struct common_quantity;
template<typename U, typename Rep1, typename Rep2, typename Rep>
struct common_quantity<quantity<U, Rep1>, quantity<U, Rep2>, Rep> {
using type = quantity<U, Rep>;
};
template<typename U1, typename Rep1, typename U2, typename Rep2, typename Rep>
requires std::same_as<typename U1::dimension, typename U2::dimension>
struct common_quantity<quantity<U1, Rep1>, quantity<U2, Rep2>, Rep> {
using type = quantity<downcasting_traits_t<unit<typename U1::dimension, common_ratio<typename U1::ratio, typename U2::ratio>>>, Rep>;
};
template<Quantity Q1, Quantity Q2, Scalar Rep = std::common_type_t<typename Q1::rep, typename Q2::rep>>
using common_quantity_t = common_quantity<Q1, Q2, Rep>::type;
// treat_as_floating_point
template<typename Rep> // todo Conceptify that
inline constexpr bool treat_as_floating_point = std::is_floating_point_v<Rep>;
// quantity_cast
namespace detail {
template<typename To, typename CR, typename CRep, bool NumIsOne = false, bool DenIsOne = false>
struct quantity_cast_impl {
template<typename Q>
static constexpr To cast(const Q& q)
{
return To(static_cast<To::rep>(static_cast<CRep>(q.count()) * static_cast<CRep>(CR::num) /
static_cast<CRep>(CR::den)));
}
};
template<typename To, typename CR, typename CRep>
struct quantity_cast_impl<To, CR, CRep, true, true> {
template<Quantity Q>
static constexpr To cast(const Q& q)
{
return To(static_cast<To::rep>(q.count()));
}
};
template<typename To, typename CR, typename CRep>
struct quantity_cast_impl<To, CR, CRep, true, false> {
template<Quantity Q>
static constexpr To cast(const Q& q)
{
return To(static_cast<To::rep>(static_cast<CRep>(q.count()) / static_cast<CRep>(CR::den)));
}
};
template<typename To, typename CR, typename CRep>
struct quantity_cast_impl<To, CR, CRep, false, true> {
template<Quantity Q>
static constexpr To cast(const Q& q)
{
return To(static_cast<To::rep>(static_cast<CRep>(q.count()) * static_cast<CRep>(CR::num)));
}
};
} // namespace detail
template<Quantity To, typename U, typename Rep>
requires std::same_as<typename To::dimension, typename U::dimension>
constexpr To quantity_cast(const quantity<U, Rep>& q)
{
using c_ratio = ratio_divide<typename U::ratio, typename To::unit::ratio>;
using c_rep = std::common_type_t<typename To::rep, Rep, intmax_t>;
using cast = detail::quantity_cast_impl<To, c_ratio, c_rep, c_ratio::num == 1, c_ratio::den == 1>;
return cast::cast(q);
}
template<Unit ToU, Scalar ToRep = double, typename U, typename Rep>
constexpr quantity<ToU, ToRep> quantity_cast(const quantity<U, Rep>& q)
{
return quantity_cast<quantity<ToU, ToRep>>(q);
}
// quantity_values
template<Scalar Rep>
struct quantity_values {
static constexpr Rep zero() noexcept { return Rep(0); }
static constexpr Rep one() noexcept { return Rep(1); }
static constexpr Rep max() noexcept { return std::numeric_limits<Rep>::max(); }
static constexpr Rep min() noexcept { return std::numeric_limits<Rep>::lowest(); }
};
// quantity
template<Unit U, Scalar Rep = double>
class quantity {
Rep value_;
public:
using unit = U;
using rep = Rep;
using dimension = U::dimension;
static_assert(!Quantity<Rep>, "rep cannot be a quantity");
quantity() = default;
quantity(const quantity&) = default;
template<std::convertible_to<rep> Rep2>
requires treat_as_floating_point<rep> || (!treat_as_floating_point<Rep2>)
constexpr explicit quantity(const Rep2& r) : value_{static_cast<rep>(r)}
{
}
template<Quantity Q2>
requires std::same_as<dimension, typename Q2::dimension> &&
std::convertible_to<typename Q2::rep, rep> &&
(treat_as_floating_point<rep> ||
(std::ratio_divide<typename Q2::unit::ratio, typename unit::ratio>::den == 1 &&
!treat_as_floating_point<typename Q2::rep>))
constexpr quantity(const Q2& q) : value_{quantity_cast<quantity>(q).count()}
{
}
quantity& operator=(const quantity& other) = default;
[[nodiscard]] constexpr rep count() const noexcept { return value_; }
[[nodiscard]] static constexpr quantity zero() noexcept { return quantity(quantity_values<Rep>::zero()); }
[[nodiscard]] static constexpr quantity one() noexcept { return quantity(quantity_values<Rep>::one()); }
[[nodiscard]] static constexpr quantity min() noexcept { return quantity(quantity_values<Rep>::min()); }
[[nodiscard]] static constexpr quantity max() noexcept { return quantity(quantity_values<Rep>::max()); }
[[nodiscard]] constexpr quantity operator+() const { return quantity(*this); }
[[nodiscard]] constexpr quantity operator-() const { return quantity(-count()); }
constexpr quantity& operator++()
{
++value_;
return *this;
}
constexpr quantity operator++(int) { return quantity(value_++); }
constexpr quantity& operator--()
{
--value_;
return *this;
}
constexpr quantity operator--(int) { return quantity(value_--); }
constexpr quantity& operator+=(const quantity& q)
{
value_ += q.count();
return *this;
}
constexpr quantity& operator-=(const quantity& q)
{
value_ -= q.count();
return *this;
}
constexpr quantity& operator*=(const rep& rhs)
{
value_ *= rhs;
return *this;
}
constexpr quantity& operator/=(const rep& rhs)
{
value_ /= rhs;
return *this;
}
constexpr quantity& operator%=(const rep& rhs)
{
value_ %= rhs;
return *this;
}
constexpr quantity& operator%=(const quantity& q)
{
value_ %= q.count();
return *this;
}
};
// clang-format off
template<typename U1, typename Rep1, typename U2, typename Rep2>
[[nodiscard]] constexpr Quantity operator+(const quantity<U1, Rep1>& lhs,
const quantity<U2, Rep2>& rhs)
requires std::same_as<typename U1::dimension, typename U2::dimension>
{
using common_rep = decltype(lhs.count() + rhs.count());
using ret = common_quantity_t<quantity<U1, Rep1>, quantity<U2, Rep2>, common_rep>;
return ret(ret(lhs).count() + ret(rhs).count());
}
template<typename U1, typename Rep1, typename U2, typename Rep2>
[[nodiscard]] constexpr Quantity operator-(const quantity<U1, Rep1>& lhs,
const quantity<U2, Rep2>& rhs)
requires std::same_as<typename U1::dimension, typename U2::dimension>
{
using common_rep = decltype(lhs.count() - rhs.count());
using ret = common_quantity_t<quantity<U1, Rep1>, quantity<U2, Rep2>, common_rep>;
return ret(ret(lhs).count() - ret(rhs).count());
}
// template<typename U, typename Rep1, Scalar Rep2>
template<typename U, typename Rep1, typename Rep2>
[[nodiscard]] constexpr Quantity operator*(const quantity<U, Rep1>& q,
const Rep2& v)
requires (!Quantity<Rep2>)
{
using common_rep = decltype(q.count()* v);
using ret = quantity<U, common_rep>;
return ret(ret(q).count() * v);
}
// template<Scalar Rep1, typename U, typename Rep2>
template<typename Rep1, typename U, typename Rep2>
[[nodiscard]] constexpr Quantity operator*(const Rep1& v,
const quantity<U, Rep2>& q)
requires (!Quantity<Rep1>)
{
return q * v;
}
template<typename U1, typename Rep1, typename U2, typename Rep2>
[[nodiscard]] constexpr Scalar operator*(const quantity<U1, Rep1>& lhs,
const quantity<U2, Rep2>& rhs)
requires std::same_as<typename U1::dimension, dim_invert_t<typename U2::dimension>>
{
using common_rep = decltype(lhs.count() * rhs.count());
using ratio = ratio_multiply<typename U1::ratio, typename U2::ratio>;
return common_rep(lhs.count()) * common_rep(rhs.count()) * common_rep(ratio::num) / common_rep(ratio::den);
}
template<typename U1, typename Rep1, typename U2, typename Rep2>
[[nodiscard]] constexpr Quantity operator*(const quantity<U1, Rep1>& lhs,
const quantity<U2, Rep2>& rhs)
requires (!std::same_as<typename U1::dimension, dim_invert_t<typename U2::dimension>>) &&
(treat_as_floating_point<decltype(lhs.count() * rhs.count())> ||
(std::ratio_multiply<typename U1::ratio, typename U2::ratio>::den == 1))
{
using dim = dimension_multiply_t<typename U1::dimension, typename U2::dimension>;
using common_rep = decltype(lhs.count() * rhs.count());
using ret = quantity<downcasting_traits_t<unit<dim, ratio_multiply<typename U1::ratio, typename U2::ratio>>>, common_rep>;
return ret(lhs.count() * rhs.count());
}
// template<Scalar Rep1, typename U, typename Rep2>
template<typename Rep1, typename U, typename Rep2>
[[nodiscard]] constexpr Quantity operator/(const Rep1& v,
const quantity<U, Rep2>& q)
requires (!Quantity<Rep1>)
{
Expects(q != std::remove_cvref_t<decltype(q)>(0));
using dim = dim_invert_t<typename U::dimension>;
using common_rep = decltype(v / q.count());
using ret = quantity<downcasting_traits_t<unit<dim, ratio<U::ratio::den, U::ratio::num>>>, common_rep>;
using den = quantity<U, common_rep>;
return ret(v / den(q).count());
}
// template<typename U, typename Rep1, Scalar Rep2>
template<typename U, typename Rep1, typename Rep2>
[[nodiscard]] constexpr Quantity operator/(const quantity<U, Rep1>& q,
const Rep2& v)
requires (!Quantity<Rep2>)
{
Expects(v != Rep2{0});
using common_rep = decltype(q.count() / v);
using ret = quantity<U, common_rep>;
return ret(ret(q).count() / v);
}
template<typename U1, typename Rep1, typename U2, typename Rep2>
[[nodiscard]] constexpr Scalar operator/(const quantity<U1, Rep1>& lhs,
const quantity<U2, Rep2>& rhs)
requires std::same_as<typename U1::dimension, typename U2::dimension>
{
Expects(rhs != std::remove_cvref_t<decltype(rhs)>(0));
using common_rep = decltype(lhs.count() / rhs.count());
using cq = common_quantity_t<quantity<U1, Rep1>, quantity<U2, Rep2>, common_rep>;
return cq(lhs).count() / cq(rhs).count();
}
template<typename U1, typename Rep1, typename U2, typename Rep2>
[[nodiscard]] constexpr Quantity operator/(const quantity<U1, Rep1>& lhs,
const quantity<U2, Rep2>& rhs)
requires (!std::same_as<typename U1::dimension, typename U2::dimension>) &&
(treat_as_floating_point<decltype(lhs.count() / rhs.count())> ||
(ratio_divide<typename U1::ratio, typename U2::ratio>::den == 1))
{
Expects(rhs != std::remove_cvref_t<decltype(rhs)>(0));
using common_rep = decltype(lhs.count() / rhs.count());
using dim = dimension_divide_t<typename U1::dimension, typename U2::dimension>;
using ret = quantity<downcasting_traits_t<unit<dim, ratio_divide<typename U1::ratio, typename U2::ratio>>>, common_rep>;
return ret(lhs.count() / rhs.count());
}
template<typename U, typename Rep1, Scalar Rep2>
[[nodiscard]] constexpr Quantity operator%(const quantity<U, Rep1>& q,
const Rep2& v)
{
using common_rep = decltype(q.count() % v);
using ret = quantity<U, common_rep>;
return ret(ret(q).count() % v);
}
template<typename U1, typename Rep1, typename U2, typename Rep2>
[[nodiscard]] constexpr Quantity operator%(const quantity<U1, Rep1>& lhs,
const quantity<U2, Rep2>& rhs)
{
using common_rep = decltype(lhs.count() % rhs.count());
using ret = common_quantity_t<quantity<U1, Rep1>, quantity<U2, Rep2>, common_rep>;
return ret(ret(lhs).count() % ret(rhs).count());
}
// clang-format on
template<typename U1, typename Rep1, typename U2, typename Rep2>
[[nodiscard]] constexpr bool operator==(const quantity<U1, Rep1>& lhs, const quantity<U2, Rep2>& rhs)
requires std::same_as<typename U1::dimension, typename U2::dimension>
{
using ct = common_quantity_t<quantity<U1, Rep1>, quantity<U2, Rep2>>;
return ct(lhs).count() == ct(rhs).count();
}
template<typename U1, typename Rep1, typename U2, typename Rep2>
[[nodiscard]] constexpr bool operator!=(const quantity<U1, Rep1>& lhs, const quantity<U2, Rep2>& rhs)
requires std::same_as<typename U1::dimension, typename U2::dimension>
{
return !(lhs == rhs);
}
template<typename U1, typename Rep1, typename U2, typename Rep2>
[[nodiscard]] constexpr bool operator<(const quantity<U1, Rep1>& lhs, const quantity<U2, Rep2>& rhs)
requires std::same_as<typename U1::dimension, typename U2::dimension>
{
using ct = common_quantity_t<quantity<U1, Rep1>, quantity<U2, Rep2>>;
return ct(lhs).count() < ct(rhs).count();
}
template<typename U1, typename Rep1, typename U2, typename Rep2>
[[nodiscard]] constexpr bool operator<=(const quantity<U1, Rep1>& lhs, const quantity<U2, Rep2>& rhs)
requires std::same_as<typename U1::dimension, typename U2::dimension>
{
return !(rhs < lhs);
}
template<typename U1, typename Rep1, typename U2, typename Rep2>
[[nodiscard]] constexpr bool operator>(const quantity<U1, Rep1>& lhs, const quantity<U2, Rep2>& rhs)
requires std::same_as<typename U1::dimension, typename U2::dimension>
{
return rhs < lhs;
}
template<typename U1, typename Rep1, typename U2, typename Rep2>
[[nodiscard]] constexpr bool operator>=(const quantity<U1, Rep1>& lhs, const quantity<U2, Rep2>& rhs)
requires std::same_as<typename U1::dimension, typename U2::dimension>
{
return !(lhs < rhs);
}
} // namespace std::experimental::units