mp_units::quantity_cast

Explicit cast of a quantity type

Synopsis

Declared in <mp-units/framework/quantity_cast.h>

template<
    QuantitySpec auto ToQS,
    typename FwdQ,
    Quantity Q = std::remove_cvref_t<FwdQ>>
requires (castable(Q::quantity_spec, ToQS)) &&
          requires { typename quantity<make_reference(ToQS, Q::unit), typename Q::rep>; }
[[nodiscard]]
constexpr
Quantity auto
quantity_cast(FwdQ&& q);

Description

This cast converts only a quantity type. It might be used to force some quantity type conversions that are not implicitly allowed but are allowed explicitly.

For example:


{.cpp}
 auto length = isq::length(42 * m);
 auto distance = quantity_cast<isq::distance>(length);

NOTE

This cast does not affect the underlying value of a number stored in a quantity.

Template Parameters

Name	Description
ToQS	a quantity specification to use for a target quantity