NAME¶

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

Synopsis¶

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)
(&a)[N]);

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¶

// Run this code

#include <cassert>
#include <cstdlib>
#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¶

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