Explicit cast of a quantity's representation
Declared in <mp-units/framework/value_cast.h>
template<
Quantity ToQ,
typename FwdQ,
Quantity Q = std::remove_cvref_t<FwdQ>>
requires (ToQ::quantity_spec == Q::quantity_spec) && UnitOf<MP_UNITS_NONCONST_TYPE(ToQ::unit), Q::quantity_spec> &&
std::constructible_from<typename ToQ::rep, typename Q::rep> &&
detail::ExplicitlyCastable<Q::unit, ToQ::unit, typename ToQ::rep>
[[nodiscard]]
constexpr
Quantity auto
value_cast(FwdQ&& q);Implicit conversions between quantities of different types are allowed only for "safe" (e.g. non-truncating) conversion. In truncating cases an explicit cast have to be used.
using ToQ = quantity<us, int>; auto q = value_cast<ToQ>(1.23 * ms);
Note that value_cast only changes the "representation aspects" (unit and representation type), but not the "meaning" (quantity type).
The return value should not be discarded.
| Name | Description |
|---|---|
| ToQ | a target quantity type to which to cast the representation |