std::experimental::to_array
From cppreference.com
< cpp | experimental
| 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
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
(library fundamentals TS v2) |
creates a std::array object whose size and optionally element type are deduced from the arguments (function template) |