quantities.h File Reference

Numeric variable proxies with embedded unit of measurement. More...

#include "larcorealg/CoreUtils/MetaUtils.h"
#include "larcorealg/CoreUtils/StdUtils.h"
#include "lardataalg/Utilities/constexpr_math.h"
#include "boost/integer/common_factor_rt.hpp"
#include <cctype>
#include <functional>
#include <limits>
#include <map>
#include <ostream>
#include <ratio>
#include <regex>
#include <string>
#include <string_view>
#include <type_traits>

Go to the source code of this file.

Classes
struct	util::quantities::concepts::details::invert_ratio< R >
struct	util::quantities::concepts::details::ratio_simplifier< R >
struct	util::quantities::concepts::details::has_unit< U >
	Trait: true_type if U is a ScaledUnit-based object. More...
struct	util::quantities::concepts::details::is_quantity< Q >
	Trait: true_type if Q is a Quantity specialization. More...
struct	util::quantities::concepts::details::has_quantity< Q >
	Trait: true_type if Q is a Quantity-based object. More...
struct	util::quantities::concepts::details::quantity_value_type< T >
struct	util::quantities::concepts::details::is_value_compatible_with< T, Q >
struct	util::quantities::concepts::details::has_value_compatible_with< T, U >
class	util::quantities::concepts::details::numeric_limits< Q >
	Limits of a quantity are the same as the underlying type. More...
struct	util::quantities::concepts::UnitBase
struct	util::quantities::concepts::Prefix< R >
struct	util::quantities::concepts::ScaledUnit< U, R >
struct	util::quantities::concepts::Quantity< Unit, T >
	A value measured in the specified unit. More...
struct	util::quantities::MissingUnit
	String representing a quantity has no unit. More...
struct	util::quantities::InvalidUnitPrefix
	String representing a quantity has unsupported unit prefix. More...
struct	util::quantities::MismatchingUnit
	String representing a quantity has incompatible unit. More...
struct	util::quantities::ValueError
	String representing a quantity has an invalid number. More...
struct	util::quantities::ExtraCharactersError
	String representing a quantity has spurious characters after the number. More...
struct	util::quantities::concepts::details::invert_ratio< std::ratio< Num, Den > >
struct	util::quantities::concepts::details::ratio_simplifier< std::ratio< Num, Den > >
struct	util::quantities::concepts::details::has_unit_impl< U, Enable >
struct	util::quantities::concepts::details::has_unit_impl< U, std::enable_if_t< util::always_true_v< typename U::unit_t > > >
struct	util::quantities::concepts::details::has_unit< U >
	Trait: true_type if U is a ScaledUnit-based object. More...
struct	util::quantities::concepts::details::is_quantity< Q >
	Trait: true_type if Q is a Quantity specialization. More...
struct	util::quantities::concepts::details::is_quantity< Quantity< Args... > >
struct	util::quantities::concepts::details::has_quantity_impl< Q, Enable >
struct	util::quantities::concepts::details::has_quantity_impl< Q, std::enable_if_t< util::always_true_v< typename Q::quantity_t > > >
struct	util::quantities::concepts::details::has_quantity< Q >
	Trait: true_type if Q is a Quantity-based object. More...
struct	util::quantities::concepts::details::quantity_value_type_impl< T, typename >
struct	util::quantities::concepts::details::always_true_v< typename T::value_t >
struct	util::quantities::concepts::details::quantity_value_type< T >
struct	util::quantities::concepts::details::is_value_compatible_with< T, Q >
struct	util::quantities::concepts::details::has_value_compatible_with< T, U >
class	util::quantities::concepts::details::numeric_limits< Q >
	Limits of a quantity are the same as the underlying type. More...
struct	std::hash< util::quantities::concepts::Quantity< Args... > >
	Hash function of a quantity is delegated to its value. More...
class	std::numeric_limits< util::quantities::concepts::Quantity< Unit, T > >
	Limits of a quantity are the same as the underlying type. More...
class	std::numeric_limits< util::quantities::concepts::Quantity< Unit, T > const >
class	std::numeric_limits< util::quantities::concepts::Quantity< Unit, T > volatile >
class	std::numeric_limits< util::quantities::concepts::Quantity< Unit, T > const volatile >

Namespaces
	util::quantities
	Types of variables with a unit.
	util::quantities::concepts
	Infrastructure for the quantities library.
	util::quantities::concepts::details
	util::quantities::prefixes
	Definitions of additional prefixes.
	util::quantities::units
	Definitions of actual units.
	util::quantities::details

Typedefs
template<typename R >
using	util::quantities::concepts::details::invert_t = typename invert_ratio< R >::type
template<typename R >
using	util::quantities::concepts::details::simplify_ratio = typename ratio_simplifier< R >::type
template<typename T >
using	util::quantities::concepts::details::quantity_value_t = typename quantity_value_type< T >::type
template<typename ARatio , typename BRatio >
using	util::quantities::concepts::simplified_ratio_multiply = details::simplify_ratio< std::ratio_multiply< ARatio, BRatio >>
	A ratio product (like std::ratio_multiply) with simplified terms. More...
template<typename NumRatio , typename DenRatio >
using	util::quantities::concepts::simplified_ratio_divide = details::simplify_ratio< std::ratio_divide< NumRatio, DenRatio >>
	A ratio division (like std::ratio_divide) with simplified terms. More...
template<typename Unit , typename Ratio , typename T >
using	util::quantities::concepts::scaled_quantity = Quantity< ScaledUnit< Unit, Ratio >, T >
	Alias for a quantity based on a scaled unit. More...
template<typename Q , typename R , typename T = typename Q::value_t>
using	util::quantities::concepts::rescale = Quantity< ScaledUnit< typename Q::unit_t::baseunit_t, R >, T >
	Type of a quantity like Q, but with a different unit scale R. More...

Functions
template<typename Ratio , typename Value >
static constexpr auto	util::quantities::concepts::details::applyRatioToValue (Value &&v)
	Applies the specified Ratio to the value in v. More...
template<typename U , typename R >
std::ostream &	util::quantities::concepts::operator<< (std::ostream &out, ScaledUnit< U, R > const &unit)
template<typename... Args>
std::ostream &	util::quantities::concepts::operator<< (std::ostream &out, Quantity< Args... > const q)
template<typename... Args>
std::string	util::quantities::concepts::to_string (ScaledUnit< Args... > const &unit)
template<typename... Args>
std::string	util::quantities::concepts::to_string (Quantity< Args... > const &q)
template<typename Quantity >
std::pair< std::string, typename Quantity::value_t >	util::quantities::details::readUnit (std::string const &str, bool unitOptional=false)
	Parses the unit of a string representing a Quantity. More...
Arithmetic operations on Quantity
These operations, as well as the ones implemented as member functions, are provided for convenience. Here the symmetric operations are defined, where different operands can be swapped.
template<typename U , typename T >
constexpr Quantity< U, T >	util::quantities::concepts::operator+ (Quantity< U, T > const q, T shift)=delete
template<typename U , typename T >
constexpr Quantity< U, T >	util::quantities::concepts::operator+ (T shift, Quantity< U, T > const q)=delete
template<typename U , typename T >
constexpr Quantity< U, T >	util::quantities::concepts::operator- (Quantity< U, T > const q, T shift)=delete
template<typename U , typename T >
constexpr Quantity< U, T >	util::quantities::concepts::operator- (T shift, Quantity< U, T > const q)=delete
template<typename U , typename T , typename OT >
constexpr std::enable_if_t< Quantity< U, T >::template is_compatible_value_v< OT >, Quantity< U, T > >	util::quantities::concepts::operator* (Quantity< U, T > const q, OT factor)
	Multiplication with a scalar. More...
template<typename U , typename T , typename OT >
constexpr std::enable_if_t< Quantity< U, T >::template is_compatible_value_v< OT >, Quantity< U, T > >	util::quantities::concepts::operator* (OT factor, Quantity< U, T > const q)
	Multiplication with a scalar. More...
template<typename AU , typename AT , typename BU , typename BT >
constexpr auto	util::quantities::concepts::operator* (Quantity< AU, AT >, Quantity< BU, BT >) -> decltype(std::declval< AT >()*std::declval< BT >())=delete
	Multiplication between quantities is forbidden. More...
template<typename U , typename T , typename OT >
constexpr std::enable_if_t< Quantity< U, T >::template is_compatible_value_v< OT >, Quantity< U, T > >	util::quantities::concepts::operator/ (Quantity< U, T > q, OT quot)
template<typename Quantity >
Quantity	util::quantities::makeQuantity (std::string_view s, bool unitOptional=false)
	Returns a quantity of the specified type parsed from a string. More...
template<typename Quantity >
Quantity	util::quantities::makeQuantity (std::string const &s, bool unitOptional=false)
	Returns a quantity of the specified type parsed from a string. More...
template<typename Quantity >
Quantity	util::quantities::makeQuantity (char const *s, bool unitOptional=false)
	Returns a quantity of the specified type parsed from a string. More...

Variables
template<typename U >
constexpr bool	util::quantities::concepts::details::has_unit_v = has_unit<U>()
	Trait: true if U is a ScaledUnit-based object. More...
template<typename Q >
constexpr bool	util::quantities::concepts::details::is_quantity_v = is_quantity<Q>()
	Trait: true if Q is a Quantity specialization. More...
template<typename Q >
constexpr bool	util::quantities::concepts::details::has_quantity_v = has_quantity<Q>()
	Trait: true if Q is a Quantity-based object. More...
template<typename T , typename Q >
constexpr bool	util::quantities::concepts::details::is_value_compatible_with_v = is_value_compatible_with<T, Q>()
	Trait: true if the type T is compatible with the value of Q. More...
template<typename T , typename U >
constexpr bool	util::quantities::concepts::details::has_value_compatible_with_v = has_value_compatible_with<T, U>()
	Trait: true if the value type of T is compatible with U's. More...

Detailed Description

Numeric variable proxies with embedded unit of measurement.

Author

Gianluca Petrillo (petri.nosp@m.llo@.nosp@m.slac..nosp@m.stan.nosp@m.ford..nosp@m.edu)

Date

October 30, 2018

See also

lardataalg/Utilities/quantites/spacetime.h

Infrastructure for a library for variables with a given unit of measurement.

Why not Boost::units?

My attempt to use Boost::units for the implementation (or directly) failed because the quantity in that library is bound to a dimension without a prefix modifier, e.g. always represents seconds, while we may need nanoseconds. Having a type representing a time in nanoseconds is not trivial, and having two types for representation of time in nanoseconds and microseconds respectively is plain complicate.

On the converse, that library provides arithmetic which is checked for dimensionality correctness. That is beyond the scope of this set of types.

Note

This code is C++17 only.

Definition in file quantities.h.