<mp-units/framework/quantity.h>
template<
typename Value,
std::derived_from<quantity> Q>
requires (!Quantity<Value>) &&
(!Reference<Value>) && detail::InvokeResultOf<quantity_spec, std::multiplies<>, const Value&, rep>
[[nodiscard]]
constexpr
QuantityOf<quantity_spec> auto
operator*(
Value const& val,
Q const& q);