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std::experimental::to_array(3) | C++ Standard Libary | std::experimental::to_array(3) |
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)
2024.06.10 | http://cppreference.com |