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std::experimental::to_array(3) C++ Standard Libary std::experimental::to_array(3)


std::experimental::to_array - std::experimental::to_array


Defined in header <experimental/array>
template <class T, std::size_t N> (library fundamentals TS
constexpr std::array<std::remove_cv_t<T>, N> to_array(T 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.


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>{});


// Run this code

#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(;
if (fd != -1)

return fd;

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

See also

make_array Creates a std::array object whose size and optionally
(library fundamentals TS v2) element type are deduced from the arguments
(function template)