CODEWITHSUNDEEP
c++c++11templatesc++14
ztik
ztik

Reputation: 3612

Transform array of elements into an array of reference_wrappered elements

I have an array of some elements. I would like to create a function that will generate an array of reference_wrapper containing the references of the element.

Something that will have an interface like:

template<typename T, size_t N>
std::array<std::reference_wrapper<T>,N> wrap(std::array<T,N>& a);

What would be the best way to do it?

Note: I don't want to use vector.

Upvotes: 1

Views: 75

Answers (1)

Rakete1111
Rakete1111

Reputation: 48978

You can do it like this. Here's a demo.

namespace detail {
    template<typename T, std::size_t N, std::size_t... Index>
    std::array<std::reference_wrapper<T>, N> wrap(std::array<T, N>& a,
                                                  std::index_sequence<Index...>) {
        return {a[Index]...};
    }
}

template<typename T, size_t N>
std::array<std::reference_wrapper<T>,N> wrap(std::array<T,N>& a) {
    return detail::wrap(a, std::make_index_sequence<N>());
}

Upvotes: 8

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