explicit type of derived_unit leads to compilation error

[mathisloge]

Following the tutorial in https://mpusz.github.io/mp-units/latest/users_guide/framework_basics/design_overview/?h=derived_unit#unit leads to an compilation error.
https://godbolt.org/z/fbcYG1n4E

How do you currently define a derived value type?

[mpusz]

Users should never instantiate derived_XXX types by themselves. Just use regular arithmetic. For example:

constexpr auto x = mp_units::si::metre / mp_units::per<mp_units::si::second>;

A similar example can be found in https://mpusz.github.io/mp-units/latest/getting_started/quick_start/#__tabbed_5_3 of our docs.