Uniform initialization by tuple

Provide Object an std::tuple constructor. You can use std::tie to assign your members:

template<typename ...Args>
Object(std::tuple<Args...> t) {
    std::tie(s, i, d) = t;
}

Now it gets automatically constructed:

std::transform(values.begin(), values.end(), std::back_inserter(objs), 
    [](auto v) -> Object {
        return { v };
    });

To reduce the amount of copying you might want to replace auto v with const auto& v and make the constructor accept a const std::tuple<Args...>& t.


Also, it's good practise to access the source container via const iterator:

std::transform(values.cbegin(), values.cend(), std::back_inserter(objs), ...


Here is a non-intrusive version (i.e. not touching Object) that extracts the number of specified data members. Note that this relies on aggregate initialization.

template <class T, class Src, std::size_t... Is>
constexpr auto createAggregateImpl(const Src& src, std::index_sequence<Is...>) {
   return T{std::get<Is>(src)...};
}

template <class T, std::size_t n, class Src>
constexpr auto createAggregate(const Src& src) {
   return createAggregateImpl<T>(src, std::make_index_sequence<n>{});
}

You invoke it like this:

std::transform(values.cbegin(), values.cend(), std::back_inserter(objs),
     [](const auto& v)->Object { return createAggregate<Object, 3>(v); });

Or, without the wrapping lambda:

std::transform(values.cbegin(), values.cend(), std::back_inserter(objs),
   createAggregate<Object, 3, decltype(values)::value_type>);

As @Deduplicator pointed out, the above helper templates implement parts of std::apply, which can be used instead.

template <class T>
auto aggregateInit()
{
   return [](auto&&... args) { return Object{std::forward<decltype(args)>(args)...}; };
}

std::transform(values.cbegin(), values.cend(), std::back_inserter(objs),
    [](const auto& v)->Object { return std::apply(aggregateInit<Object>(), v); });

Since C++17, you might use std::make_from_tuple:

std::transform(values.begin(),
               values.end(),
               std::back_inserter(objs),
               [](const auto& t)
        {
            return std::make_from_tuple<Object>(t);
        });

Note: requires appropriated constructor for Object.