5 Quantities and units library [quantities]

5.4 Reference [qty.ref]

5.4.4 Unit [qty.unit]

5.4.4.2 Magnitude [qty.unit.mag]

5.4.4.2.5 Utilities [qty.unit.mag.utils]

friend consteval bool is-positive-integral-power(unit-magnitude x); // exposition only
Returns: false if x has a negative or rational exponent, and true otherwise.
template<auto... Ms2> friend consteval auto common-magnitude(unit-magnitude, unit-magnitude<Ms2...>); // exposition only
Returns: The largest magnitude C such that each input magnitude is expressible by only positive powers relative to C.