<mp-units/framework/value_cast.h>
template<
typename ToRep,
Unit auto ToU,
typename FwdQ,
Quantity Q = std::remove_cvref_t<FwdQ>>
requires (MP_UNITS_WEAK_UNIT_OF(MP_UNITS_REMOVE_CONST(decltype(ToU)), Q::quantity_spec)) &&
RepresentationOf<ToRep, Q::quantity_spec> && std::constructible_from<ToRep, typename Q::rep> &&
detail::SaneScaling<Q::unit, ToU, ToRep>
[[nodiscard]]
constexpr
Quantity auto
value_cast(FwdQ&& q);