std::experimental::to_array (3) - Linux Man Pages

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

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 v2)
constexpr std::array<std::remove_cv_t<T>, N> to_array(T (&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 <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
make_array (function template)