vector::emplace_back multiple items

{ text has been reformatted to ~70 chars per line. -mod }

I came up with the following solution to work around the fact that
vector::emplace_back allows the insertion of only one single element
at a time.
My requirements are the use of a move-only type (see struct A below),
so the initializer_list version of the vector ctor is a no-go.

Following is i) the definition of the A type, ii) the template functions
implementing the logic, iii) a sample main function.

#include <iterator>
#include <iostream>
#include <utility>
#include <vector>
using namespace std;

template<typename Container, typename Element>
void emplace_all_helper(Container& c, Element&& e) {
    c.emplace_back(forward<Element>(e));
}
template<typename Container, typename Element, typename ...Elements>
void emplace_all_helper(Container& c, Element&& e, Elements&&... args) {
    emplace_all_helper(c, forward<Element>(e));
    emplace_all_helper(c, forward<Element>(args)...);
}

template<typename Container, typename ...Elements>
void emplace_all(Container& c, Elements&&... args) {
    c.reserve(c.size() + sizeof...(args));
    emplace_all_helper(c, forward<Elements>(args)...);
}

struct A {
    int m_v;

    A(int v) : m_v {v} { }
    A(A&& other) noexcept { m_v = other.m_v; }
    A& operator=(A&& other) noexcept { m_v = other.m_v; return *this; }

    A() = delete;
    A(const A& other) = delete;
    A& operator=(const A& other) = delete;

};

ostream& operator<<(ostream& os, const A& a) {
    os << a.m_v;
    return os;
}

int main() {
    vector<A> va;
    emplace_all(va, A(1), A(2), A(3));

    copy(begin(va), end(va), ostream_iterator<A>(cout, ", ")); // prints 1,
2, 3,
    cout << endl;
}

Does anybody have an alternative / better idea how to achieve something
similar?

Thanks,

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