C++ Stack container template with constexpr support, by Jason Turner

Stack.h++

template<typename T, std::size_t Size>
struct Stack
{
  T m_data[Size]();
  std::size_t pos = 0;

  template<typename ... Arg>
  void constexpr emplace_back(Arg &&... arg)
  {
    m_data[pos] = T{std::forward<Arg>(arg)...};
    ++pos;
  }

  constexpr T pop_back()
  {
    --pos;
    return m_data[pos];
  }

  constexpr bool empty() const
  {
    return pos == 0;
  }

  constexpr std::size_t size() const
  {
    return pos;
  }
};