Function memcpy

gil/std.str.hpp:34–38

}

static constexpr auto memcpy(auto dst, auto src, auto size) noexcept {
  using _impl_::idx;

  return for_(idx = 0, idx < size, ++idx)(dst[*idx] = src[*idx]);
}

static constexpr auto end(auto ch) noexcept {
  return ch == none_ || ch == '\0';