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Merge branch 'downcasting_2.0'

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Mateusz Pusz committed 2020-09-09 20:31:03 +02:00
2 parents dcc2d24c8e 72ed03fbf9
commit e367afed71
22 files changed
+300 -145
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src/include/units/bits/common_quantity.h
+8 -3
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@@ -23,6 +23,8 @@
#pragma once
#include <units/bits/dimension_op.h>
#include <units/bits/equivalent.h>
#include <units/quantity_cast.h>
namespace units {
@@ -55,9 +57,12 @@ struct common_quantity_impl<quantity<D1, U1, Rep1>, quantity<D2, U2, Rep2>, Rep>
template<typename D1, typename U1, typename Rep1, typename D2, typename U2, typename Rep2, typename Rep>
struct common_quantity_impl<quantity<D1, U1, Rep1>, quantity<D2, U2, Rep2>, Rep> {
using dimension = conditional<is_specialization_of<D1, unknown_dimension>, D2, D1>;
static constexpr ratio r1 = D1::base_units_ratio * U1::ratio;
static constexpr ratio r2 = D2::base_units_ratio * U2::ratio;
using type = quantity<D1, downcast_unit<D1, common_ratio(r1, r2)>, Rep>;
static constexpr ratio cr = common_ratio(r1, r2);
using unit = downcast_unit<dimension, cr / dimension::base_units_ratio>;
using type = quantity<dimension, unit, Rep>;
};
template<typename D, typename U, typename Rep>
@@ -66,7 +71,7 @@ quantity_point<D, U, Rep> common_quantity_point_impl(quantity<D, U, Rep>);
} // namespace detail
template<Quantity Q1, Quantity Q2, ScalableNumber Rep = std::common_type_t<typename Q1::rep, typename Q2::rep>>
requires equivalent_dim<typename Q1::dimension, typename Q2::dimension>
requires equivalent<typename Q1::dimension, typename Q2::dimension>
using common_quantity = TYPENAME detail::common_quantity_impl<Q1, Q2, Rep>::type;
template<QuantityPoint QP1, QuantityPoint QP2>
@@ -79,7 +84,7 @@ using common_quantity_point = decltype(
namespace std {
template<units::Quantity Q1, units::Quantity Q2>
requires units::equivalent_dim<typename Q1::dimension, typename Q2::dimension>
requires units::equivalent<typename Q1::dimension, typename Q2::dimension>
struct common_type<Q1, Q2> {
using type = units::common_quantity<Q1, Q2>;
};
src/include/units/bits/dimension_op.h
-34
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@@ -27,40 +27,6 @@
namespace units {
// equivalent_dim
namespace detail {
template<BaseDimension D1, BaseDimension D2>
using equivalent_base_dim = std::conjunction<std::bool_constant<D1::symbol == D2::symbol>,
same_unit_reference<typename D1::base_unit, typename D2::base_unit>>;
template<Dimension D1, Dimension D2>
struct equivalent_dim_impl : std::false_type {};
template<BaseDimension D1, BaseDimension D2>
struct equivalent_dim_impl<D1, D2> : std::disjunction<is_same<D1, D2>, equivalent_base_dim<D1, D2>> {};
template<Exponent E1, Exponent E2>
struct equivalent_exp : std::false_type {};
template<BaseDimension Dim1, std::intmax_t Num, std::intmax_t Den, BaseDimension Dim2>
struct equivalent_exp<exponent<Dim1, Num, Den>, exponent<Dim2, Num, Den>> : equivalent_dim_impl<Dim1, Dim2> {};
template<DerivedDimension D1, DerivedDimension D2>
struct equivalent_derived_dim : std::false_type {};
template<typename... Es1, typename... Es2>
requires (sizeof...(Es1) == sizeof...(Es2))
struct equivalent_derived_dim<derived_dimension_base<Es1...>, derived_dimension_base<Es2...>> : std::conjunction<equivalent_exp<Es1, Es2>...> {};
template<DerivedDimension D1, DerivedDimension D2>
struct equivalent_dim_impl<D1, D2> : std::disjunction<is_same<D1, D2>, equivalent_derived_dim<downcast_base_t<D1>, downcast_base_t<D2>>> {};
} // namespace detail
template<Dimension D1, Dimension D2>
inline constexpr bool equivalent_dim = detail::equivalent_dim_impl<D1, D2>::value;
/**
* @brief Unknown dimension
*
src/include/units/bits/equivalent.h
+98
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@@ -0,0 +1,98 @@
// 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/concepts.h>
#include <units/unit.h>
namespace units {
namespace detail {
template<typename T, typename U>
struct equivalent_impl : std::false_type {
};
// units
template<Unit U1, Unit U2>
struct equivalent_impl<U1, U2> : std::disjunction<std::is_same<U1, U2>, std::is_base_of<U1, U2>, std::is_base_of<U2, U1>> {};
// dimensions
template<BaseDimension D1, BaseDimension D2>
struct equivalent_base_dim :
std::conjunction<std::bool_constant<D1::symbol == D2::symbol>,
same_unit_reference<typename D1::base_unit, typename D2::base_unit>> {
};
template<BaseDimension D1, BaseDimension D2>
struct equivalent_impl<D1, D2> : std::disjunction<std::is_same<D1, D2>, equivalent_base_dim<D1, D2>> {
};
template<Exponent E1, Exponent E2>
struct equivalent_exp : std::false_type {
};
template<BaseDimension Dim1, std::intmax_t Num, std::intmax_t Den, BaseDimension Dim2>
struct equivalent_exp<exponent<Dim1, Num, Den>, exponent<Dim2, Num, Den>> : equivalent_impl<Dim1, Dim2> {
};
template<DerivedDimension D1, DerivedDimension D2>
struct equivalent_derived_dim : std::false_type {
};
template<typename... Es1, typename... Es2>
requires(sizeof...(Es1) == sizeof...(Es2))
struct equivalent_derived_dim<derived_dimension_base<Es1...>, derived_dimension_base<Es2...>> :
std::conjunction<equivalent_exp<Es1, Es2>...> {
};
template<DerivedDimension D1, DerivedDimension D2>
struct equivalent_impl<D1, D2> :
std::disjunction<std::is_same<D1, D2>, std::is_base_of<D1, D2>, std::is_base_of<D2, D1>,
equivalent_derived_dim<downcast_base_t<D1>, downcast_base_t<D2>>> {
};
// additionally accounts for unknown dimensions
template<Unit U1, Dimension D1, Unit U2, Dimension D2>
struct equivalent_unit : std::disjunction<equivalent_impl<U1, U2>,
std::bool_constant<U1::ratio / dimension_unit<D1>::ratio == U2::ratio / dimension_unit<D2>::ratio>> {};
// quantities and quantity points
template<typename Q1, typename Q2>
requires (Quantity<Q1> && Quantity<Q2>) || (QuantityPoint<Q1> && QuantityPoint<Q2>)
struct equivalent_impl<Q1, Q2> : std::disjunction<std::is_same<Q1, Q2>,
std::conjunction<equivalent_impl<typename Q1::dimension, typename Q2::dimension>,
equivalent_unit<typename Q1::unit, typename Q1::dimension,
typename Q2::unit, typename Q2::dimension>>> {};
} // namespace detail
template<typename T, typename U>
inline constexpr bool equivalent = detail::equivalent_impl<T, U>::value;
} // namespace units
src/include/units/bits/external/downcasting.h
Vendored
+44 -13
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@@ -25,44 +25,75 @@
#include <units/bits/external/hacks.h>
#include <type_traits>
#ifdef DOWNCAST_MODE
#if DOWNCAST_MODE < 0 || DOWNCAST_MODE > 2
#error "Invalid DOWNCAST_MODE value"
#endif
#else
#define DOWNCAST_MODE 2
#endif
namespace units {
template<typename BaseType>
struct downcast_base {
using downcast_base_type = BaseType;
friend auto downcast_guide(downcast_base);
friend auto downcast_poison_pill(downcast_base);
};
template<typename T>
concept Downcastable =
requires {
typename T::downcast_base_type;
} &&
requires { typename T::downcast_base_type; } &&
std::derived_from<T, downcast_base<typename T::downcast_base_type>>;
template<typename Target, Downcastable T>
struct downcast_child : T {
friend auto downcast_guide(typename downcast_child::downcast_base /* base */) { return Target(); }
};
namespace detail {
template<typename T>
concept has_downcast =
concept has_downcast_guide =
requires {
downcast_guide(std::declval<downcast_base<T>>());
};
template<typename T>
concept has_downcast_poison_pill =
requires {
downcast_poison_pill(std::declval<downcast_base<T>>());
};
template<typename Target, Downcastable T>
struct downcast_child : T {
friend auto downcast_guide(typename T::downcast_base)
{ return Target(); }
};
template<Downcastable T>
struct downcast_poison : T {
friend auto downcast_poison_pill(typename T::downcast_base)
{ return true; }
};
enum class downcast_mode {
off = 0, // no downcasting at all
on = 1, // downcasting always forced -> compile-time errors in case of duplicated definitions
automatic = 2 // downcasting automatically enabled if no collisions are present
};
template<typename Target, Downcastable T, downcast_mode mode = static_cast<downcast_mode>(DOWNCAST_MODE)>
struct downcast_dispatch : std::conditional_t<mode == downcast_mode::off, T,
std::conditional_t<mode == downcast_mode::automatic && has_downcast_guide<T>,
downcast_poison<T>, downcast_child<Target, T>>> {};
namespace detail {
template<typename T>
constexpr auto downcast_impl()
{
if constexpr (has_downcast<T>)
if constexpr(has_downcast_guide<T> && !has_downcast_poison_pill<T>)
return decltype(downcast_guide(std::declval<downcast_base<T>>()))();
else
return T();
}
} // namespace detail
}
template<Downcastable T>
using downcast = decltype(detail::downcast_impl<T>());