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refactor: multiplication and division by scalars was a bad idea for `…
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…Complex` and `Vector`
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@mpusz
mpusz committed Nov 28, 2024
1 parent f99a73a commit a223c08
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Showing 2 changed files with 50 additions and 42 deletions.
82 changes: 40 additions & 42 deletions src/core/include/mp-units/framework/representation_concepts.h
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Original file line number Diff line number Diff line change
Expand Up @@ -168,22 +168,18 @@ constexpr bool disable_complex = false;
namespace detail {

template<typename T>
concept Complex =
(!disable_complex<T>) && WeaklyRegular<T> && Scalar<value_type_t<T>> &&
std::constructible_from<T, value_type_t<T>, value_type_t<T>> && requires(T a, T b, value_type_t<T> s) {
// complex operations
{ -a } -> std::common_with<T>;
{ a + b } -> std::common_with<T>;
{ a - b } -> std::common_with<T>;
{ a* b } -> std::common_with<T>;
{ a / b } -> std::common_with<T>;
{ a* s } -> std::common_with<T>;
{ s* a } -> std::common_with<T>;
{ a / s } -> std::common_with<T>;
::mp_units::real(a);
::mp_units::imag(a);
::mp_units::modulus(a);
};
concept Complex = (!disable_complex<T>) && WeaklyRegular<T> && requires(T a, T b) {
// complex operations
{ -a } -> std::common_with<T>;
{ a + b } -> std::common_with<T>;
{ a - b } -> std::common_with<T>;
{ a* b } -> std::common_with<T>;
{ a / b } -> std::common_with<T>;
::mp_units::real(a);
::mp_units::imag(a);
::mp_units::modulus(a);
requires std::constructible_from<T, decltype(::mp_units::real(a)), decltype(::mp_units::imag(a))>;
};

namespace magnitude_impl {

Expand Down Expand Up @@ -233,23 +229,19 @@ constexpr bool disable_vector = false;
namespace detail {

template<typename T>
concept Vector =
(!disable_vector<T>) && WeaklyRegular<T> && Scalar<value_type_t<T>> && requires(T a, T b, value_type_t<T> s) {
// vector operations
{ -a } -> std::common_with<T>;
{ a + b } -> std::common_with<T>;
{ a - b } -> std::common_with<T>;
{ a* s } -> std::common_with<T>;
{ s* a } -> std::common_with<T>;
{ a / s } -> std::common_with<T>;
::mp_units::magnitude(a);
// TODO should we check for the below as well (e.g., when `size() > 1` or `2`)
// { zero_vector<T>() } -> Vector;
// { unit_vector(a) } -> Vector;
// { scalar_product(a, b) } -> Scalar;
// { vector_product(a, b) } -> Vector;
// { tensor_product(a, b) } -> Tensor2;
};
concept Vector = (!disable_vector<T>) && WeaklyRegular<T> && requires(T a, T b) {
// vector operations
{ -a } -> std::common_with<T>;
{ a + b } -> std::common_with<T>;
{ a - b } -> std::common_with<T>;
::mp_units::magnitude(a);
// TODO should we also check for the below (e.g., when `size() > 1` or `2`)
// { zero_vector<T>() } -> Vector;
// { unit_vector(a) } -> Vector;
// { scalar_product(a, b) } -> Scalar;
// { vector_product(a, b) } -> Vector;
// { tensor_product(a, b) } -> Tensor2;
};

// TODO provide when some actual operations will be required
// template<typename T>
Expand All @@ -266,27 +258,33 @@ constexpr bool is_quantity = false;
template<typename T>
using scaling_factor_type_t = conditional<treat_as_floating_point<T>, long double, std::intmax_t>;

// TODO how can we use `(!Quantity<T>)` below?
template<typename T>
concept ScalarRepresentation = (!is_quantity<T>) && Scalar<T> && requires(T a, T b, scaling_factor_type_t<T> f) {
concept ScalarRepresentation = (!is_quantity<T>) && Scalar<T> && requires(T v, scaling_factor_type_t<T> f) {
// scaling
{ a* f } -> std::common_with<T>;
{ f* a } -> std::common_with<T>;
{ a / f } -> std::common_with<T>;
{ v* f } -> std::common_with<T>;
{ f* v } -> std::common_with<T>;
{ v / f } -> std::common_with<T>;
};

template<typename T>
concept ComplexRepresentation = (!is_quantity<T>) && Complex<T> && requires(T a, T b, scaling_factor_type_t<T> f) {
concept ComplexRepresentation = (!is_quantity<T>) && Complex<T> && requires(T v, scaling_factor_type_t<T> f) {
// scaling
// TODO The below conversion to `T` is an exception compared to other representation types
// `std::complex<T>` * `U` do not work, but `std::complex<T>` is convertible from `U`
// Maybe expose this as a customization point?
{ a* T(f) } -> std::common_with<T>;
{ T(f) * a } -> std::common_with<T>;
{ a / T(f) } -> std::common_with<T>;
{ v* T(f) } -> std::common_with<T>;
{ T(f) * v } -> std::common_with<T>;
{ v / T(f) } -> std::common_with<T>;
};

template<typename T>
concept VectorRepresentation = (!is_quantity<T>) && Vector<T>;
concept VectorRepresentation = (!is_quantity<T>) && Vector<T> && requires(T v, scaling_factor_type_t<T> f) {
// scaling
{ v* f } -> std::common_with<T>;
{ f* v } -> std::common_with<T>;
{ v / f } -> std::common_with<T>;
};

// template<typename T>
// concept TensorRepresentation = (!is_quantity<T>) && Tensor<T>;
Expand Down
10 changes: 10 additions & 0 deletions test/static/concepts_test.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -434,4 +434,14 @@ static_assert(!QuantityPointLike<quantity<isq::time[si::second]>>);
static_assert(!QuantityPointLike<quantity_point<si::metre, my_origin>>);
static_assert(!QuantityPointLike<int>);

// Quantity Characters

static_assert(detail::Scalar<quantity<one>>);
static_assert(detail::Scalar<quantity<one, int>>);
static_assert(!detail::Scalar<quantity_point<one>>);
static_assert(!detail::Scalar<quantity_point<si::metre>>);
// TODO it would be make the below work
static_assert(!detail::Scalar<quantity<si::metre>>);
static_assert(!detail::Scalar<quantity<isq::speed[si::metre / si::second], int>>);

} // namespace

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