util::quantities::concepts::Quantity< Unit, T > Struct Template Reference

A value measured in the specified unit. More...

#include <quantities.h>

Public Types
using	value_t = T
	Type of the stored value. More...
using	unit_t = Unit
	The unit and scale of this quantity. More...
using	quantity_t = Quantity< Unit, T >
	The type of this class. More...
using	baseunit_t = typename unit_t::baseunit_t
	Description of the unscaled unit. More...

Public Member Functions
	Quantity ()=default
	Constructor: value is left uninitialized. More...
constexpr	Quantity (value_t v)
	Constructor: takes a value in the intended representation. More...
template<typename Q , typename std::enable_if_t< details::is_quantity_v< Q >> * = nullptr>
constexpr	Quantity (Q q)
	Constructor: converts from another quantity. More...
constexpr value_t	value () const
	Returns the value of the quantity. More...
constexpr	operator value_t () const
	Explicit conversion to the base quantity. More...
template<typename OQ >
constexpr OQ	convertInto () const
	Convert this quantity into the specified one. More...
template<typename OU , typename OT >
constexpr auto	operator+ (Quantity< OU, OT > const other) const -> quantity_t
template<typename OU , typename OT >
constexpr auto	operator- (Quantity< OU, OT > const other) const -> quantity_t
template<typename OU , typename OT >
constexpr auto	plus (Quantity< OU, OT > const other) const -> quantity_t
template<typename OU , typename OT >
constexpr auto	minus (Quantity< OU, OT > const other) const -> quantity_t
template<typename OU , typename OT >
constexpr auto	operator/ (Quantity< OU, OT > const q) const -> value_t
template<typename OU , typename OT >
auto	operator+= (Quantity< OU, OT > const other) -> quantity_t &
template<typename OU , typename OT >
auto	operator-= (Quantity< OU, OT > const other) -> quantity_t &
Asymmetric operand arithmetic operations
These arithmetic operations take care of preserving the quantity through them. Not all possible (or reasonable) operations are supported yet. Some operations that may be symmetric (like multiplication by a scalar) are implemented as free functions rather than methods. Note These operations are essentially provided by convenience. There are many cases (corner and not) where the implicit conversion to the base type kicks in. This implementation does not aim to prevent that from happening, but requests are welcome to add features to allow that not to happen, with some care of the user. Operators + and - support only quantity operands of the same type, and no plain number operand. The rational behind this is that when writing a + b with a and b two homogeneous quantities, we expect to be able to use b + a as well. But it a and b are different types (e.g. one is second, the other is millisecond), an arbitrary choice has to be made on which type the result should be, and having different types for a + b and b + a is not acceptable. If the intention is clear, methods plus() and minus() are provided with the understanding that e.g. a.plus(b) explicitly requires the result to be of type a.
template<typename OU , typename OT >
constexpr quantity_t	operator+ (Quantity< OU, OT > const other) const
	Returns a quantity sum of this and other (must have same unit). More...
template<typename OU , typename OT >
constexpr quantity_t	operator- (Quantity< OU, OT > const other) const
template<typename OU , typename OT >
constexpr quantity_t	plus (Quantity< OU, OT > const other) const
	Returns a quantity sum of this and other. More...
template<typename OU , typename OT >
constexpr quantity_t	minus (Quantity< OU, OT > const other) const
	Returns a quantity difference of this and other. More...
template<typename OU , typename OT >
constexpr value_t	operator/ (Quantity< OU, OT > q) const
	Division by a quantity, returns a pure number. More...
template<typename OU , typename OT >
quantity_t &	operator+= (Quantity< OU, OT > const other)
	Add the other quantity (possibly concerted) to this one. More...
template<typename OU , typename OT >
quantity_t &	operator-= (Quantity< OU, OT > const other)
	Subtract the other quantity (possibly concerted) to this one. More...
template<typename OT >
std::enable_if_t < std::is_arithmetic_v< OT > , quantity_t & >	operator*= (OT factor)
	Scale this quantity by a factor. More...
template<typename OT >
std::enable_if_t < std::is_arithmetic_v< OT > , quantity_t & >	operator/= (OT quot)
	Scale the quantity dividing it by a quotient. More...
constexpr quantity_t	operator+ () const
	Returns a quantity with same value. More...
constexpr quantity_t	operator- () const
	Returns a quantity with same value but the sign flipped. More...
constexpr quantity_t	abs () const
	Returns a quantity with the absolute value of this one. More...
Comparisons.
Comparisons with plain numbers are managed by implicit conversion. More care is needed for quantities. Comparisons between two quantity instances a and b work this way: if a and b do not have the same unit, they are not comparable if a and b have the same unit, one is converted to the other and the comparison is performed there if a and b have the same scaled unit, their values are compared directly Value storage types are compared according to C++ rules.
template<typename OU , typename OT >
constexpr bool	operator== (Quantity< OU, OT > const other) const
template<typename OU , typename OT >
constexpr bool	operator!= (Quantity< OU, OT > const other) const
template<typename OU , typename OT >
constexpr bool	operator>= (Quantity< OU, OT > const other) const
template<typename OU , typename OT >
constexpr bool	operator> (Quantity< OU, OT > const other) const
template<typename OU , typename OT >
constexpr bool	operator<= (Quantity< OU, OT > const other) const
template<typename OU , typename OT >
constexpr bool	operator< (Quantity< OU, OT > const other) const

Static Public Member Functions
template<typename U >
static constexpr quantity_t	castFrom (U value)
	Returns a new quantity initialized with the specified value. More...

Private Attributes
value_t	fValue {}
	Stored value. More...

Access to the scaled unit.
template<typename U >
static constexpr bool	is_compatible_value_v = details::is_value_compatible_with_v<U, value_t>
	Whether U is a value type compatible with value_t. More...
template<typename U >
static constexpr bool	has_compatible_value_v = details::has_value_compatible_with_v<U, value_t>
	Whether U has (or is) a value type compatible with value_t. More...
static constexpr unit_t	unit ()
	Returns an object with as type the scaled unit (unit_t). More...
static constexpr baseunit_t	baseUnit ()
	Returns an object with as type the base unit (baseunit_t). More...
static auto	unitName ()
	Returns the full name of the unit, in a string-like object. More...
static auto	unitSymbol ()
	Returns the symbol of the unit, in a string-like object. More...
template<typename OU >
static constexpr bool	sameBaseUnitAs ()
	Returns whether this quantity has the same base unit as OU. More...
template<typename OU >
static constexpr bool	sameUnitAs ()
	Returns whether this quantity has same unit and scale as OU. More...
template<typename U >
static constexpr bool	isCompatibleValue ()
	Returns whether U is a value type compatible with value_t. More...
template<typename U >
static constexpr bool	hasCompatibleValue ()

Detailed Description

template<typename Unit, typename T = double>
struct util::quantities::concepts::Quantity< Unit, T >

A value measured in the specified unit.

---

Template Parameters

Unit	the scaled unit type representing the unit of this quantity
T	type of base value

A Quantity instance is a glorified number of type T (or, value_t). The Quantity class adds to it the explicit documentation of the unit the value is measured in, plus some attempt to preserve that information:

• a Quantity type will carry the information of its unit with the type

• quantities must be assigned other quantities: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp} using util::quantities::milliampere;

  milliampere i; i = 2.5; // ERROR! what is 2.5? i = milliampere(2.5);

  milliampere i2 { 2.5 }; // SPECIAL, allowed only in construction i2 = i1; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• can be converted, implicitly or explicitly, to its plain value: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp} using util::quantities::milliampere;

  milliampere i { 6.0 }; double v = i; // implicit conversion v = double(i); // explicit conversion v = i.value(); // even more explicit conversion ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• weakly resists attempts to mess with units ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp} milliampere mi { 4.0 }; microampere ui { 500.0 }; mi = ui; // now mi == 0.5 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• weakly attempts to preserve the unit information ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp} using namespace util::quantities; using namespace util::quantities::electronics_literals;

  milliampere mi { 4.0 }; microampere ui { 500.0 };

  mi += ui; // 4.5 mA mi *= ui; // ERROR! what does this even mean?? mi += 5.0; // ERROR! mi += milliampere(3.0); // 7.5 mA mi += 2.0_ma; // 9.5 mA mi + ui; // ERROR! (arbitrary whether to represent in mA or uA) mi + 5.0; // ERROR! (as above) mi / 5.0; // milliampere{1.9} mi - 5_mA; // milliampere{4.5} ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

(milliampere and microampere are hypotetical instantiations of Quantity template class from util::quantities, and they also have a literal conversion to correctly interpret things like 2.0_ma or 7_A)

Implementation details

• method signatures usually pass Quantity objects by value; it is assumed that the type T is simple enough that copying it is faster than passing around its reference, and that any overhead is optimized out by the compiler

Definition at line 566 of file quantities.h.

Member Typedef Documentation

template<typename Unit, typename T = double>

using util::quantities::concepts::Quantity< Unit, T >::baseunit_t = typename unit_t::baseunit_t

Description of the unscaled unit.

Definition at line 575 of file quantities.h.

template<typename Unit, typename T = double>

using util::quantities::concepts::Quantity< Unit, T >::quantity_t = Quantity<Unit, T>

The type of this class.

Definition at line 572 of file quantities.h.

template<typename Unit, typename T = double>

using util::quantities::concepts::Quantity< Unit, T >::unit_t = Unit

The unit and scale of this quantity.

Definition at line 571 of file quantities.h.

template<typename Unit, typename T = double>

using util::quantities::concepts::Quantity< Unit, T >::value_t = T

Type of the stored value.

Definition at line 570 of file quantities.h.

Constructor & Destructor Documentation

template<typename Unit, typename T = double>

util::quantities::concepts::Quantity< Unit, T >::Quantity ( )

explicitdefault

Constructor: value is left uninitialized.

template<typename Unit, typename T = double>

constexpr util::quantities::concepts::Quantity< Unit, T >::Quantity ( value_t  v )

inlineexplicit

Constructor: takes a value in the intended representation.

Definition at line 584 of file quantities.h.

: fValue(v) {}

template<typename Unit, typename T = double>

template<typename Q , typename std::enable_if_t< details::is_quantity_v< Q >> * = nullptr>

constexpr util::quantities::concepts::Quantity< Unit, T >::Quantity ( Q  q )

inline

Constructor: converts from another quantity.

Template Parameters

Q	type of the other quantity

Parameters

q	quantity to be converted from

Quantities are required to be in the same unit (unit scale may differ). The value in q is converted from its native scale into the one of this quantity.

Definition at line 599 of file quantities.h.

        : fValue
          {unit_t::template fromRepr<typename Q::unit_t::ratio>(q.value()) }
        {
          static_assert(sameBaseUnitAs<Q>(),
            "Can't construct from quantity with different base unit"
            );
        }

Member Function Documentation

template<typename Unit, typename T = double>

constexpr quantity_t util::quantities::concepts::Quantity< Unit, T >::abs ( ) const

inline

Returns a quantity with the absolute value of this one.

Definition at line 693 of file quantities.h.

        { return quantity_t(util::abs(value())); }

template<typename Unit, typename T = double>

static constexpr baseunit_t util::quantities::concepts::Quantity< Unit, T >::baseUnit ( )

inlinestatic

Returns an object with as type the base unit (baseunit_t).

Definition at line 748 of file quantities.h.

{ return {}; }

template<typename Unit, typename T = double>

template<typename U >

static constexpr quantity_t util::quantities::concepts::Quantity< Unit, T >::castFrom ( U  value )

inlinestatic

Returns a new quantity initialized with the specified value.

Template Parameters

U	type to initialize the quantity with

Parameters

value

the value to initialize the quantity with

Returns

a new Quantity object initialized with value

The value is cast into value_t via static_cast().

Example: be Tick a quantity based on an integral value, like util::quantities::tick, and detClocks an instance of detinfo::DetectorClocks:

double const tickDuration = detClocks.OpticalClock().TickPeriod();

auto const triggerTick
  = Tick::castFrom(detClocks.TriggerTime() / tickDuration);

triggerTick will be of type Tick and will denote the number of the tick (0-based) within which detClocks.TriggerTime() fell.

Definition at line 825 of file quantities.h.

        { return quantity_t{ static_cast<value_t>(value) }; }

template<typename Unit, typename T = double>

template<typename OQ >

constexpr OQ util::quantities::concepts::Quantity< Unit, T >::convertInto ( ) const

inline

Convert this quantity into the specified one.

Definition at line 801 of file quantities.h.

{ return OQ(*this); }

template<typename Unit, typename T = double>

template<typename U >

static constexpr bool util::quantities::concepts::Quantity< Unit, T >::hasCompatibleValue ( )

inlinestatic

Returns whether U has (or is) a value type compatible with value_t.

Definition at line 792 of file quantities.h.

        { return quantity_t::has_compatible_value_v<U>; }

template<typename Unit, typename T = double>

template<typename U >

static constexpr bool util::quantities::concepts::Quantity< Unit, T >::isCompatibleValue ( )

inlinestatic

Returns whether U is a value type compatible with value_t.

Definition at line 786 of file quantities.h.

        { return quantity_t::is_compatible_value_v<U>; }

template<typename Unit, typename T = double>

template<typename OU , typename OT >

constexpr quantity_t util::quantities::concepts::Quantity< Unit, T >::minus

(

Quantity< OU, OT > const

other

)

const

Returns a quantity difference of this and other.

template<typename Unit, typename T = double>

template<typename OU , typename OT >

constexpr auto util::quantities::concepts::Quantity< Unit, T >::minus

(

Quantity< OU, OT > const

other

)

const -> quantity_t

Definition at line 1340 of file quantities.h.

{
  static_assert
   (sameBaseUnitAs<OU>(), "Can't subtract quantities with different base unit");

  // if the two quantities have the same *scaled* unit, add
  if constexpr (sameUnitAs<OU>()) {
    return quantity_t(fValue - other.value());
    return *this;
  }
  else {
    // otherwise, they have same base unit but different scale: convert `other`
    return (*this - quantity_t(other));
  }
} // util::quantities::concepts::Quantity<>::minus()

template<typename Unit, typename T = double>

constexpr util::quantities::concepts::Quantity< Unit, T >::operator value_t ( ) const

inlineexplicit

Explicit conversion to the base quantity.

Definition at line 612 of file quantities.h.

        { return value(); }

template<typename U , typename T >

template<typename OU , typename OT >

constexpr bool util::quantities::concepts::Quantity< U, T >::operator!=

(

Quantity< OU, OT > const

other

)

const

Definition at line 1448 of file quantities.h.

{
  static_assert
    (sameBaseUnitAs<OU>(), "Can't compare quantities with different base unit");

  // if the two quantities have the same *scaled* unit, just compare the values
  if constexpr (sameUnitAs<OU>()) {
    return value() != other.value();
  }
  else {
    // otherwise, they have same base unit but different scale: convert `other`
    return *this != quantity_t(other);
  }
} // util::quantities::concepts::Quantity<>::operator!=()

template<typename Unit, typename T = double>

template<typename OT >

std::enable_if_t<std::is_arithmetic_v<OT>, quantity_t&> util::quantities::concepts::Quantity< Unit, T >::operator*= ( OT  factor )

inline

Scale this quantity by a factor.

Definition at line 679 of file quantities.h.

{ fValue *= factor; return *this; }

template<typename Unit, typename T = double>

template<typename OU , typename OT >

constexpr quantity_t util::quantities::concepts::Quantity< Unit, T >::operator+

(

Quantity< OU, OT > const

other

)

const

Returns a quantity sum of this and other (must have same unit).

template<typename Unit, typename T = double>

constexpr quantity_t util::quantities::concepts::Quantity< Unit, T >::operator+ ( ) const

inline

Returns a quantity with same value.

Definition at line 687 of file quantities.h.

{ return quantity_t(value()); }

template<typename Unit, typename T = double>

template<typename OU , typename OT >

constexpr auto util::quantities::concepts::Quantity< Unit, T >::operator+

(

Quantity< OU, OT > const

other

)

const -> quantity_t

Definition at line 1290 of file quantities.h.

{
  static_assert(std::is_same<Quantity<OU, OT>, quantity_t>(),
    "Only quantities with exactly the same unit can be added."
    );
  return quantity_t(value() + other.value());
} // util::quantities::concepts::Quantity<>::operator+

template<typename Unit, typename T = double>

template<typename OU , typename OT >

quantity_t& util::quantities::concepts::Quantity< Unit, T >::operator+=

(

Quantity< OU, OT > const

other

)

Add the other quantity (possibly concerted) to this one.

template<typename Unit, typename T = double>

template<typename OU , typename OT >

auto util::quantities::concepts::Quantity< Unit, T >::operator+=

(

Quantity< OU, OT > const

other

)

-> quantity_t&

Definition at line 1383 of file quantities.h.

{
  static_assert
    (sameBaseUnitAs<OU>(), "Can't add quantities with different base unit");

  // if the two quantities have the same *scaled* unit, add
  if constexpr (sameUnitAs<OU>()) {
    fValue += other.value();
    return *this;
  }
  else {
    // otherwise, they have same base unit but different scale: convert `other`
    return (*this += quantity_t(other));
  }
} // util::quantities::concepts::Quantity<>::operator+=()

template<typename Unit, typename T = double>

template<typename OU , typename OT >

constexpr quantity_t util::quantities::concepts::Quantity< Unit, T >::operator-

(

Quantity< OU, OT > const

other

)

const

Returns a quantity difference of this and other (must have same unit).

template<typename Unit, typename T = double>

constexpr quantity_t util::quantities::concepts::Quantity< Unit, T >::operator- ( ) const

inline

Returns a quantity with same value but the sign flipped.

Definition at line 690 of file quantities.h.

{ return quantity_t(-value()); }

template<typename Unit, typename T = double>

template<typename OU , typename OT >

constexpr auto util::quantities::concepts::Quantity< Unit, T >::operator-

(

Quantity< OU, OT > const

other

)

const -> quantity_t

Definition at line 1304 of file quantities.h.

{
  static_assert(std::is_same<Quantity<OU, OT>, quantity_t>(),
    "Only quantities with exactly the same unit can be subtracted."
    );
  return quantity_t(value() - other.value());
} // util::quantities::concepts::Quantity<>::operator+

template<typename Unit, typename T = double>

template<typename OU , typename OT >

quantity_t& util::quantities::concepts::Quantity< Unit, T >::operator-=

(

Quantity< OU, OT > const

other

)

Subtract the other quantity (possibly concerted) to this one.

template<typename Unit, typename T = double>

template<typename OU , typename OT >

auto util::quantities::concepts::Quantity< Unit, T >::operator-=

(

Quantity< OU, OT > const

other

)

-> quantity_t&

Definition at line 1405 of file quantities.h.

{
  static_assert(sameBaseUnitAs<OU>(),
    "Can't subtract quantities with different base unit"
    );

  // if the two quantities have the same *scaled* unit, add
  if constexpr (sameUnitAs<OU>()) {
    fValue -= other.value();
    return *this;
  }
  else {
    // otherwise, they have same base unit but different scale: convert `other`
    return (*this -= quantity_t(other));
  }
} // util::quantities::concepts::Quantity<>::operator-=()

template<typename Unit, typename T = double>

template<typename OU , typename OT >

constexpr value_t util::quantities::concepts::Quantity< Unit, T >::operator/

(

Quantity< OU, OT >

q

)

const

Division by a quantity, returns a pure number.

template<typename Unit, typename T = double>

template<typename OU , typename OT >

constexpr auto util::quantities::concepts::Quantity< Unit, T >::operator/

(

Quantity< OU, OT > const

q

)

const -> value_t

Definition at line 1362 of file quantities.h.

{
  static_assert
    (sameBaseUnitAs<OU>(), "Can't divide quantities with different base unit");

  // if the two quantities have the same *scaled* unit, divide
  if constexpr (sameUnitAs<OU>()) {
    return value() / q.value();
  }
  else {
    // otherwise, they have same base unit but different scale: convert `other`
    return (*this) / quantity_t(q);
  }
} // util::quantities::concepts::Quantity<>::operator/(Quantity)

template<typename Unit, typename T = double>

template<typename OT >

std::enable_if_t<std::is_arithmetic_v<OT>, quantity_t&> util::quantities::concepts::Quantity< Unit, T >::operator/= ( OT  quot )

inline

Scale the quantity dividing it by a quotient.

Definition at line 684 of file quantities.h.

{ fValue /= quot; return *this; }

template<typename U , typename T >

template<typename OU , typename OT >

constexpr bool util::quantities::concepts::Quantity< U, T >::operator<

(

Quantity< OU, OT > const

other

)

const

Definition at line 1508 of file quantities.h.

{
  static_assert
    (sameBaseUnitAs<OU>(), "Can't compare quantities with different base unit");

  // if the two quantities have the same *scaled* unit, just compare the values
  if constexpr (sameUnitAs<OU>()) {
    return value() < other.value();
  }
  else {
    // otherwise, they have same base unit but different scale: convert `other`
    return *this < quantity_t(other);
  }
} // util::quantities::concepts::Quantity<>::operator<()

template<typename U , typename T >

template<typename OU , typename OT >

constexpr bool util::quantities::concepts::Quantity< U, T >::operator<=

(

Quantity< OU, OT > const

other

)

const

Definition at line 1468 of file quantities.h.

{
  static_assert
    (sameBaseUnitAs<OU>(), "Can't compare quantities with different base unit");

  // if the two quantities have the same *scaled* unit, just compare the values
  if constexpr (sameUnitAs<OU>()) {
    return value() <= other.value();
  }
  else {
    // otherwise, they have same base unit but different scale: convert `other`
    return *this <= quantity_t(other);
  }
} // util::quantities::concepts::Quantity<>::operator<=()

template<typename U , typename T >

template<typename OU , typename OT >

constexpr bool util::quantities::concepts::Quantity< U, T >::operator==

(

Quantity< OU, OT > const

other

)

const

Definition at line 1428 of file quantities.h.

{
  static_assert
    (sameBaseUnitAs<OU>(), "Can't compare quantities with different base unit");

  // if the two quantities have the same *scaled* unit, just compare the values
  if constexpr (sameUnitAs<OU>()) {
    return value() == other.value();
  }
  else {
    // otherwise, they have same base unit but different scale: convert `other`
    return *this == quantity_t(other);
  }
} // util::quantities::concepts::Quantity<>::operator==()

template<typename U , typename T >

template<typename OU , typename OT >

constexpr bool util::quantities::concepts::Quantity< U, T >::operator>

(

Quantity< OU, OT > const

other

)

const

Definition at line 1528 of file quantities.h.

{
  static_assert
    (sameBaseUnitAs<OU>(), "Can't compare quantities with different base unit");

  // if the two quantities have the same *scaled* unit, just compare the values
  if constexpr (sameUnitAs<OU>()) {
    return value() > other.value();
  }
  else {
    // otherwise, they have same base unit but different scale: convert `other`
    return *this > quantity_t(other);
  }
} // util::quantities::concepts::Quantity<>::operator>()

template<typename U , typename T >

template<typename OU , typename OT >

constexpr bool util::quantities::concepts::Quantity< U, T >::operator>=

(

Quantity< OU, OT > const

other

)

const

Definition at line 1488 of file quantities.h.

{
  static_assert
    (sameBaseUnitAs<OU>(), "Can't compare quantities with different base unit");

  // if the two quantities have the same *scaled* unit, just compare the values
  if constexpr (sameUnitAs<OU>()) {
    return value() >= other.value();
  }
  else {
    // otherwise, they have same base unit but different scale: convert `other`
    return *this >= quantity_t(other);
  }
} // util::quantities::concepts::Quantity<>::operator>=()

template<typename Unit, typename T = double>

template<typename OU , typename OT >

constexpr quantity_t util::quantities::concepts::Quantity< Unit, T >::plus

(

Quantity< OU, OT > const

other

)

const

Returns a quantity sum of this and other.

template<typename Unit, typename T = double>

template<typename OU , typename OT >

constexpr auto util::quantities::concepts::Quantity< Unit, T >::plus

(

Quantity< OU, OT > const

other

)

const -> quantity_t

Definition at line 1318 of file quantities.h.

{
  static_assert
    (sameBaseUnitAs<OU>(), "Can't add quantities with different base unit");

  // if the two quantities have the same *scaled* unit, add
  if constexpr (sameUnitAs<OU>()) {
    return quantity_t(fValue + other.value());
    return *this;
  }
  else {
    // otherwise, they have same base unit but different scale: convert `other`
    return (*this + quantity_t(other));
  }
} // util::quantities::concepts::Quantity<>::operator+()

template<typename Unit, typename T = double>

template<typename OU >

static constexpr bool util::quantities::concepts::Quantity< Unit, T >::sameBaseUnitAs ( )

inlinestatic

Returns whether this quantity has the same base unit as OU.

Parameters

OU	any type with baseunit_t type (including ScaledUnit, Quantity, Interval...)

Definition at line 762 of file quantities.h.

        { return unit_t::template sameBaseUnitAs<OU>(); }

template<typename Unit, typename T = double>

template<typename OU >

static constexpr bool util::quantities::concepts::Quantity< Unit, T >::sameUnitAs ( )

inlinestatic

Returns whether this quantity has same unit and scale as OU.

Parameters

OU	any type with unit_t type (including ScaledUnit, Quantity, Interval...)

Definition at line 771 of file quantities.h.

        { return unit_t::template sameUnitAs<OU>(); }

template<typename Unit, typename T = double>

static constexpr unit_t util::quantities::concepts::Quantity< Unit, T >::unit ( )

inlinestatic

Returns an object with as type the scaled unit (unit_t).

Definition at line 745 of file quantities.h.

{ return {}; }

template<typename Unit, typename T = double>

static auto util::quantities::concepts::Quantity< Unit, T >::unitName ( )

inlinestatic

Returns the full name of the unit, in a string-like object.

Definition at line 751 of file quantities.h.

{ return unit_t::name(); }

template<typename Unit, typename T = double>

static auto util::quantities::concepts::Quantity< Unit, T >::unitSymbol ( )

inlinestatic

Returns the symbol of the unit, in a string-like object.

Definition at line 754 of file quantities.h.

{ return unit_t::symbol(); }

template<typename Unit, typename T = double>

constexpr value_t util::quantities::concepts::Quantity< Unit, T >::value ( ) const

inline

Returns the value of the quantity.

Definition at line 609 of file quantities.h.

{ return fValue; }

Member Data Documentation

template<typename Unit, typename T = double>

value_t util::quantities::concepts::Quantity< Unit, T >::fValue {}

private

Stored value.

Definition at line 830 of file quantities.h.

template<typename Unit, typename T = double>

template<typename U >

constexpr bool util::quantities::concepts::Quantity< Unit, T >::has_compatible_value_v = details::has_value_compatible_with_v<U, value_t>

static

Whether U has (or is) a value type compatible with value_t.

Definition at line 782 of file quantities.h.

template<typename Unit, typename T = double>

template<typename U >

constexpr bool util::quantities::concepts::Quantity< Unit, T >::is_compatible_value_v = details::is_value_compatible_with_v<U, value_t>

static

Whether U is a value type compatible with value_t.

Definition at line 777 of file quantities.h.

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The documentation for this struct was generated from the following file:

• quantities.h