xo-unit: + Quantity.add support

This commit is contained in:
Roland Conybeare 2024-04-23 15:36:11 -04:00
commit e1d7f62ca6
6 changed files with 120 additions and 13 deletions

View file

@ -44,13 +44,13 @@ namespace xo {
constexpr Quantity reciprocal() const { return Quantity(1.0 / scale_, unit_.reciprocal()); }
template <typename OtherQuantity>
template <typename Quantity2>
static constexpr
auto multiply(const Quantity & x, const OtherQuantity & y) {
auto multiply(const Quantity & x, const Quantity2 & y) {
using r_repr_type = std::common_type_t<typename Quantity::repr_type,
typename OtherQuantity::repr_type>;
typename Quantity2::repr_type>;
using r_int_type = std::common_type_t<typename Quantity::ratio_int_type,
typename OtherQuantity::ratio_int_type>;
typename Quantity2::ratio_int_type>;
auto rr = detail::nu_product(x.unit(), y.unit());
@ -85,6 +85,30 @@ namespace xo {
rr.natural_unit_);
}
template <typename Quantity2>
static constexpr
auto add(const Quantity & x, const Quantity2 & y) {
using r_repr_type = std::common_type_t<typename Quantity::repr_type,
typename Quantity2::repr_type>;
using r_int_type = std::common_type_t<typename Quantity::ratio_int_type,
typename Quantity2::ratio_int_type>;
/* conversion to get y in same units as x: multiply by y/x */
auto rr = detail::nu_ratio(y.unit(), x.unit());
if (rr.natural_unit_.is_dimensionless()) {
r_repr_type r_scale = (static_cast<r_repr_type>(x.scale())
+ (::sqrt(rr.outer_scale_sq_)
* rr.outer_scale_exact_.template to<r_repr_type>()
* static_cast<r_repr_type>(y.scale())));
return Quantity<r_repr_type, r_int_type>(r_scale, x.unit_.template to_repr<r_int_type>());
} else {
/* units don't match! */
return Quantity<r_repr_type, r_int_type>(std::numeric_limits<Repr>::quiet_NaN(),
x.unit_.template to_repr<r_int_type>());
}
}
private:
/** @brief quantity represents this multiple of a unit amount **/
@ -106,23 +130,47 @@ namespace xo {
/** note: won't have constexpr result until c++26 (when ::sqrt(), ::pow() are constexpr)
**/
template <typename Quantity, typename OtherQuantity>
template <typename Repr = double,
typename Int = std::int64_t>
inline constexpr Quantity<Repr, Int>
natural_unit_qty(const natural_unit<Int> & nu) {
return Quantity<Repr, Int>(1.0, nu);
}
/** note: won't have constexpr result until c++26 (when ::sqrt(), ::pow() are constexpr)
**/
template <typename Quantity, typename Quantity2>
requires quantity2_concept<Quantity> && quantity2_concept<Quantity2>
constexpr auto
operator* (const Quantity & x, const OtherQuantity & y)
operator* (const Quantity & x, const Quantity2 & y)
{
return Quantity::multiply(x, y);
}
/** note: won't have constexpr result until c++26 (when ::sqrt(), ::pow() are constexpr)
**/
template <typename Quantity, typename OtherQuantity>
template <typename Quantity, typename Quantity2>
requires quantity2_concept<Quantity> && quantity2_concept<Quantity2>
constexpr auto
operator/ (const Quantity & x, const OtherQuantity & y)
operator/ (const Quantity & x, const Quantity2 & y)
{
return Quantity::divide(x, y);
}
/** note: won't have constexpr result until c++26 (when ::sqrt(), ::pow() are constexpr)
**/
template <typename Quantity, typename Quantity2>
requires quantity2_concept<Quantity> && quantity2_concept<Quantity2>
constexpr auto
operator+ (const Quantity & x, const Quantity2 & y)
{
return Quantity::add(x, y);
}
namespace unit {
constexpr auto nanogram = natural_unit_qty(nu2::nanogram);
}
} /*namespace qty*/
} /*namespace xo*/
/** end Quantity.hpp **/