#include <cstdint>

template<typename T>
class span {
   T* ptr_;
   std::size_t len_;
public:
   using value_type = std::remove_cv_t<T>; //primarily needed if used with templates

   span(T* ptr, std::size_t len) noexcept : ptr_{ptr}, len_{len} {}

   T& operator[](int i) noexcept { return *ptr_[i]; }
   T const& operator[](int i) const noexcept { return *ptr_[i]; }

   bool empty() const noexcept { return len_ == 0; }
   auto size() const noexcept { return len_; }

   auto begin() noexcept { return ptr_; }   
   auto begin() const noexcept { return ptr_; }
   auto end() noexcept { return ptr_ + len_; }	
   auto end() const noexcept { return ptr_ + len_; }
};
static_assert(_MSVC_LANG <= 201703L, "Remember to switch to std::span");