[#mp_units-operator_star-00]
= xref:mp_units.adoc[mp_units]::operator*
:relfileprefix: ../
:mrdocs:

Multiplication operators

== Synopses

Declared in `<mp‐units/framework/reference.h>`

Multiplies a unit by a reference


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
[[nodiscard]]
consteval
/* implementation-defined */
xref:mp_units/operator_star-02b.adoc[operator*](
    U1 u1,
    xref:mp_units/reference-0b2.adoc[reference] r);
----

[.small]#xref:mp_units/operator_star-02b.adoc[_» more..._]#

Multiplies a reference by a unit


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
[[nodiscard]]
consteval
/* implementation-defined */
xref:mp_units/operator_star-0f.adoc[operator*](
    xref:mp_units/reference-0b2.adoc[reference] r,
    U2 u2);
----

[.small]#xref:mp_units/operator_star-0f.adoc[_» more..._]#

Multiplies two references


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
[[nodiscard]]
consteval
/* implementation-defined */
xref:mp_units/operator_star-05.adoc[operator*](
    xref:mp_units/reference-0b2.adoc[reference] r1,
    xref:mp_units/reference-0b2.adoc[reference<Q2, U2>] r2);
----

[.small]#xref:mp_units/operator_star-05.adoc[_» more..._]#

Deleted overload rejecting `reference * quantity` in favor of `quantity * reference`


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<
    xref:mp_units/Reference-0ba.adoc[Reference] R,
    typename Q>
requires Quantity<std::remove_cvref_t<Q>>
constexpr
auto
xref:mp_units/operator_star-0d.adoc[operator*](
    R r,
    Q&& q) = delete;
----

[.small]#xref:mp_units/operator_star-0d.adoc[_» more..._]#

Deleted overload rejecting `reference * representation` in favor of `representation * reference`


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<
    xref:mp_units/Reference-0ba.adoc[Reference] R,
    typename Rep>
requires RepresentationOf<std::remove_cvref_t<Rep>, get_quantity_spec(R{})>
constexpr
auto
xref:mp_units/operator_star-0c.adoc[operator*](
    R r,
    Rep&& rep) = delete;
----

[.small]#xref:mp_units/operator_star-0c.adoc[_» more..._]#

Rebinds a quantity to a reference obtained by multiplying its own reference by `R`


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<
    typename FwdQ,
    xref:mp_units/Reference-0ba.adoc[Reference] R,
    xref:mp_units/Quantity-0c.adoc[Quantity] Q = std::remove_cvref_t<FwdQ>>
[[nodiscard]]
constexpr
xref:mp_units/Quantity-0c.adoc[Quantity] auto
xref:mp_units/operator_star-022.adoc[operator*](
    FwdQ&& q,
    R r);
----

[.small]#xref:mp_units/operator_star-022.adoc[_» more..._]#

Constructs a quantity from a representation value and a reference


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<
    typename FwdRep,
    xref:mp_units/Reference-0ba.adoc[Reference] R,
    xref:mp_units/RepresentationOf.adoc[RepresentationOf<get_quantity_spec(R{})>] Rep = std::remove_cvref_t<FwdRep>>
requires (!detail::OffsetUnit<decltype(get_unit(R{}))>)
[[nodiscard]]
constexpr
xref:mp_units/quantity-01.adoc[quantity<R{}, Rep>]
xref:mp_units/operator_star-06f.adoc[operator*](
    FwdRep&& lhs,
    R r);
----

[.small]#xref:mp_units/operator_star-06f.adoc[_» more..._]#

Deprecated constructor of a quantity from a representation value and an offset‐unit reference


[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template<
    typename FwdRep,
    xref:mp_units/Reference-0ba.adoc[Reference] R,
    xref:mp_units/RepresentationOf.adoc[RepresentationOf<get_quantity_spec(R{})>] Rep = std::remove_cvref_t<FwdRep>>
requires detail::OffsetUnit<decltype(get_unit(R{}))>
[[deprecated("2.3.0: References using offset units (e.g., temperatures) should be constructed with the `delta` or `point` helpers")]]
constexpr
auto
xref:mp_units/operator_star-067.adoc[operator*](
    FwdRep&& lhs,
    R r);
----

[.small]#xref:mp_units/operator_star-067.adoc[_» more..._]#

== Return Value

* a reference resulting from multiplying the quantity specification and the unit
* a reference resulting from multiplying the quantity specifications and the units
* quantity holding the same numerical value as `q`, with reference `Q::reference * R{}`
* quantity of reference `r` holding the value of `lhs`

== Parameters

[cols="1,4"]
|===
| Name| Description
| *u1*
| the unit to multiply
| *r*
| the reference to multiply by
| *u2*
| the unit to multiply by
| *r1*
| the reference to multiply
| *r2*
| the reference to multiply by
| *q*
| quantity operand (unused)
| *rep*
| representation operand (unused)
| *lhs*
| representation value to become the quantity's numerical value
|===


[.small]#Created with https://www.mrdocs.com[MrDocs]#