Declared in <mp-units/framework/representation_concepts.h>
template<
typename T,
auto V>
concept RepresentationOf = (QuantitySpec<MP_UNITS_REMOVE_CONST(decltype(V))> &&
((detail::QuantityKindSpec<MP_UNITS_REMOVE_CONST(decltype(V))> && detail::SomeRepresentation<T>) ||
(detail::RepresentationOfOrder<T, detail::order_of(get_character(V))> &&
detail::RepresentationOfField<T, detail::field_of(get_character(V))>))) ||
detail::RepresentationOfCharacter<T, V>;