traitModifier[L <: HList, U, V] extends DepFn2[L, (U) ⇒ V]
Type class supporting replacement of the first element of type U from this HList with the result of
its transformation via a given function into a new element of type V.
Available only if this HList contains an element of type U.
Type class supporting replacement of the first element of type U from this
HListwith the result of its transformation via a given function into a new element of type V. Available only if thisHListcontains an element of typeU.