std::experimental::to_array

From cppreference.com
Defined in header <experimental/array>
template <class T, std::size_t N>
constexpr std::array<std::remove_cv_t<T>, N> to_array(T (&a)[N]);
(library fundamentals TS v2)

Creates a std::array from the built-in array a. The elements of the std::array are copy-initialized from the corresponding element of a.

Parameters

a - the built-in array to be used to initialize the std::array

Return value

An std::array object whose elements are copy-initialized from the corresponding element of a.

Possible implementation

namespace detail {
template <class T, std::size_t N, std::size_t... I>
constexpr std::array<std::remove_cv_t<T>, N>
    to_array_impl(T (&a)[N], std::index_sequence<I...>)
{
    return { {a[I]...} };
}
}

template <class T, std::size_t N>
constexpr std::array<std::remove_cv_t<T>, N> to_array(T (&a)[N])
{
    return detail::to_array_impl(a, std::make_index_sequence<N>{});
}

Example

#include <cstdlib>
#include <cassert>
#include <experimental/array>
#include <unistd.h>

// mkstemp(3) that works
template <std::size_t N>
int tempfd(char const (&tmpl)[N])
{
    auto s = std::experimental::to_array(tmpl);
    int fd = mkstemp(s.data());
    if (fd != -1)
        unlink(s.data());

    return fd;
}

int main()
{
    int fd = tempfd("/tmp/test.XXXXXX");
    int rt = close(fd);
    assert(rt == 0);
}


See also

Creates a std::array object whose size and optionally element type are deduced from the arguments
(function template)