mp_units::quantity_point::operator‐‐

constexpr
quantity_point&
operator‐‐() &
requires requires { ‐‐quantity_from_origin_is_an_implementation_detail_; };

[[nodiscard]]
constexpr
quantity_point
operator‐‐(int)
requires requires { quantity_from_origin_is_an_implementation_detail_‐‐; };