xo-numeric/xo-unit/include/xo/unit/basis_unit.hpp
Roland Conybeare d1fa15f248 Add 'xo-unit/' from commit 'b531e382c2'
git-subtree-dir: xo-unit
git-subtree-mainline: e9ee6992ca
git-subtree-split: b531e382c2
2025-05-10 21:29:43 -05:00

240 lines
13 KiB
C++

/** @file basis_unit.hpp **/
#pragma once
#include "native_unit.hpp"
#include "dimension.hpp"
//#include "basis_unit_abbrev.hpp"
#include "xo/ratio/ratio.hpp"
namespace xo {
namespace qty {
using bu_abbrev_type = flatstring<16>;
using scalefactor_ratio_type = xo::ratio::ratio<std::int64_t>;
using scalefactor2x_ratio_type = xo::ratio::ratio<__int128>;
/** @class basis_unit
* @brief A dimensionless multiple of a single natively-specified basis dimension
*
* For example "3600 minutes" or "1e-6 grams".
*
* Members are public so that a @c basis_unit instance qualifies as a 'structural type',
* and therefore may be used as a non-type template parameter.
**/
struct basis_unit {
public:
/** @defgroup basis-unit-constructors basis_unit constructors **/
///@{
/** sentinel basis unit: invalid dimension and zero scalefactor **/
constexpr basis_unit() = default;
/** basis unit representing multiple @p scalefactor of native dimension @p **/
constexpr basis_unit(dimension native_dim,
const scalefactor_ratio_type & scalefactor)
: native_dim_{native_dim},
scalefactor_{scalefactor}
{}
///@}
/** @defgroup basis-unit-access-methods basis_unit access methods **/
///@{
/** get @c native_dim member **/
constexpr dimension native_dim() const { return native_dim_; }
/** get @c scalefactor member **/
constexpr const scalefactor_ratio_type & scalefactor() const { return scalefactor_; }
///@}
public: /* public so instance can be a non-type template parameter (a structural type) */
/** @defgroup basis-unit-instance-vars basis_unit instance variables **/
///@{
/** @brief identifies a native unit, e.g. time **/
dimension native_dim_ = dimension::invalid;
/** @brief this unit defined as multiple scalefactor times native unit **/
scalefactor_ratio_type scalefactor_ = {};
///@}
};
/** @defgroup basis-unit-comparison-support basis_unit comparisons **/
///@{
/** @c true iff basis units are equal;
* both native dimension and scalefactor must be equal
**/
inline constexpr bool
operator==(const basis_unit & x, const basis_unit & y)
{
return ((x.native_dim_ == y.native_dim_)
&& (x.scalefactor_ == y.scalefactor_));
}
/** @c true iff bass units are not equal **/
inline constexpr bool
operator!=(const basis_unit & x, const basis_unit & y)
{
return ((x.native_dim_ != y.native_dim_)
|| (x.scalefactor_ != y.scalefactor_));
}
///@}
namespace detail {
/** @brief namespace for basis-unit constants and helpers **/
namespace bu {
// ----- mass -----
constexpr basis_unit mass_unit(std::int64_t num, std::int64_t den) {
return basis_unit(dimension::mass, scalefactor_ratio_type(num, den));
}
/** @defgroup basis-unit-mass-units basis_unit mass units **/
///@{
/** basis unit of 10^-12 grams **/
constexpr basis_unit picogram = mass_unit( 1, 1000000000000);
/** basis unit of 10^-9 grams **/
constexpr basis_unit nanogram = mass_unit( 1, 1000000000);
/** basis unit of 10^-6 grams **/
constexpr basis_unit microgram = mass_unit( 1, 1000000);
/** basis unit of 10^-3 grams **/
constexpr basis_unit milligram = mass_unit( 1, 1000);
/** basis unit of 1 gram **/
constexpr basis_unit gram = mass_unit( 1, 1);
/** basis unit of 10^3 grams **/
constexpr basis_unit kilogram = mass_unit( 1000, 1);
/** basis unit of 10^6 grams = 10^3 kilograms **/
constexpr basis_unit tonne = mass_unit( 1000000, 1);
/** basis unit of 10^9 grams = 10^6 kilograms = 10^3 tonnes **/
constexpr basis_unit kilotonne = mass_unit( 1000000000, 1);
/** basis unit of 10^12 grams = 10^9 kilograms = 10^6 tonnes **/
constexpr basis_unit megatonne = mass_unit( 1000000000000, 1);
/** basis unit of 10^15 grams = 10^12 kilograms = 10^9 tonnes **/
constexpr basis_unit gigatonne = mass_unit(1000000000000000, 1);
///@}
// ----- distance -----
constexpr basis_unit distance_unit(std::int64_t num, std::int64_t den) {
return basis_unit(dimension::distance, scalefactor_ratio_type(num, den));
}
/** @defgroup basis-unit-distance-units basis_unit distance units **/
///@{
/* US spelling */
/** basis unit of 10^-12 meters **/
constexpr basis_unit picometer = distance_unit( 1, 1000000000000);
/** basis unit of 10^-9 meters **/
constexpr basis_unit nanometer = distance_unit( 1, 1000000000);
/** basis unit of 10^-6 meters **/
constexpr basis_unit micrometer = distance_unit( 1, 1000000);
/** basis unit of 10^-3 meters **/
constexpr basis_unit millimeter = distance_unit( 1, 1000);
/** basis unit of 1 meter **/
constexpr basis_unit meter = distance_unit( 1, 1);
/** basis unit of 10^3 meters **/
constexpr basis_unit kilometer = distance_unit( 1000, 1);
/** basis unit of 10^6 meters (for form's sake -- not commonly used) **/
constexpr basis_unit megameter = distance_unit( 1000000, 1);
/** basis unit of 10^9 meters (for form's sake -- not commonly used) **/
constexpr basis_unit gigameter = distance_unit( 1000000000, 1);
/** basis unit of 1 light-second = distance light travels in a vacuum in 1 second **/
constexpr basis_unit lightsecond = distance_unit( 299792458, 1);
/** basis unit of 1 astronomical unit, representing approximate radius of earth orbit. **/
constexpr basis_unit astronomicalunit = distance_unit( 149597870700, 1);
/* Int'l spelling */
/** international spelling for picometer **/
constexpr basis_unit picometre = picometer;
/** international spelling for nanometer **/
constexpr basis_unit nanometre = nanometer;
/** international spelling for micrometer **/
constexpr basis_unit micrometre = micrometer;
/** international spelling for millimeter **/
constexpr basis_unit millimetre = millimeter;
/** international spelling for meter **/
constexpr basis_unit metre = meter;
/** international spelling for kilometer **/
constexpr basis_unit kilometre = kilometer;
/** international spelling for megameter **/
constexpr basis_unit megametre = megameter;
/** international spelling for gigameter **/
constexpr basis_unit gigametre = gigameter;
/** @brief basis-unit representing 1 inch; defined as exactly 1/12 feet **/
constexpr basis_unit inch = distance_unit( 3048, 120000);
/** @brief basis-unit representing 1 foot; defined as exactly 0.3048 meters **/
constexpr basis_unit foot = distance_unit( 3048, 10000);
/** @brief basis-unit representing 1 yard; defined as exactly 3 feet **/
constexpr basis_unit yard = distance_unit( 3*3048, 10000);
/** @brief basis-unit representing 1 mile; defined as exactly 1760 yards = 5280 feet **/
constexpr basis_unit mile = distance_unit( 5280*3048, 10000);
///@}
// ----- time -----
constexpr basis_unit time_unit(std::int64_t num, std::int64_t den) {
return basis_unit(dimension::time, scalefactor_ratio_type(num, den));
}
/** @defgroup basis-unit-time-units basis_unit time units **/
///@{
/** basis unit of 10^-12 seconds **/
constexpr basis_unit picosecond = time_unit( 1, 1000000000000);
/** basis unit of 10^-9 seconds **/
constexpr basis_unit nanosecond = time_unit( 1, 1000000000);
/** basis unit of 10^-6 seconds **/
constexpr basis_unit microsecond = time_unit( 1, 1000000);
/** basis unit of 10^-3 seconds **/
constexpr basis_unit millisecond = time_unit( 1, 1000);
/** basis unit of 1 second **/
constexpr basis_unit second = time_unit( 1, 1);
/** basis unit of 1 minute = 60 seconds **/
constexpr basis_unit minute = time_unit( 60, 1);
/** basis unit of 1 hour = 3600 seconds **/
constexpr basis_unit hour = time_unit( 3600, 1);
/** basis unit of 1 day = exactly 24 hours **/
constexpr basis_unit day = time_unit( 24*3600, 1);
/** basis unit of 1 week = exactly 7 days **/
constexpr basis_unit week = time_unit( 7*24*3600, 1);
/** basis unit of 1 month = exactly 30 days **/
constexpr basis_unit month = time_unit( 30*24*3600, 1);
/** basis unit of 1 year, defined as 365.25 days **/
constexpr basis_unit year = time_unit( (365*24+6)*3600, 1);
/* alt conventions used in finance */
/** basis unit of 1 year365 = exactly 365 days **/
constexpr basis_unit year365 = time_unit( 365*24*3600, 1);
/** basis unit of 1 year360 = exactly 360 days **/
constexpr basis_unit year360 = time_unit( 360*24*3600, 1);
/** basis unit of 1 year250 = exactly 250 days.
* Approximate number of business days in one year
**/
constexpr basis_unit year250 = time_unit( 250*24*3600, 1);
//constexpr basis_unit century = time_unit( 100L*(365*24+6)*3600, 1);
//constexpr basis_unit millenium = time_unit(1000L*(365*24+6)*3600, 1);
///@}
// ----- currency -----
/** @defgroup basis-unit-misc-units basis_unit miscellaneous units**/
///@{
constexpr basis_unit currency_unit(std::int64_t num, std::int64_t den) {
return basis_unit(dimension::currency, scalefactor_ratio_type(num, den));
}
/** pseudounit -- placeholder for any actual currency amount **/
constexpr basis_unit currency = currency_unit(1, 1);
// ----- price -----
constexpr basis_unit price_unit(std::int64_t num, std::int64_t den) {
return basis_unit(dimension::price, scalefactor_ratio_type(num, den));
}
/** psuedounit -- context-dependent interpretation for a screen price **/
constexpr basis_unit price = price_unit(1, 1);
///@}
} /*namespace bu*/
} /*namespace detail*/
} /*namespace qty*/
} /*namespace xo*/
/** end basis_unit.hpp **/