Function UniqueBy

util/generic/algorithm.h:302–304

template <class T, class TGetKey>
constexpr T UniqueBy(T f, T l, const TGetKey& getKey) {
    return Unique(f, l, [&](auto&& left, auto&& right) { return getKey(left) == getKey(right); });
}

template <class C>
void SortUnique(C& c) {