问不存在动态多态的模板参数解耦

EN

// Pass pointer to `Ringbuffer` to use in other classes
class Ringbuffer 
{
    uint8_t* _bufPtr; // Downside is you need to store additional 2 fields
    int _bufSize;
protected:
    constexpr Ringbuffer(uint8_t* bufPtr, int bufSize) : _bufPtr(bufPtr), _bufSize(bufSize) { }

    template <std::size_t N>
    constexpr Ringbuffer(uint8_t (&buffer)[N]) : _bufPtr(buffer), _bufSize(N) {}

    constexpr Ringbuffer(const Ringbuffer&) = default;
    Ringbuffer& operator=(const Ringbuffer&) = default;
public:
    void push(uint8_t); // Work with _bufPtr / _bufSize instead of _buffer
    uint8_t getNext();
};

// Passed pointers to `Ringbuffer` will actually point to `RingbufferFinal`
// with static buffer with parametrized size
template<int BUFFER_SIZE>
class RingbufferFinal : public Ringbuffer 
{
protected:
    uint8_t _buffer[BUFFER_SIZE];

public:
    constexpr RingbufferFinal() : Ringbuffer(_buffer) {}

    constexpr RingbufferFinal(const RingbufferFinal<BUFFER_SIZE>& other) :
        Ringbuffer(*this)
    {
        // Copy contents of other._buffer only.
        // _bufPtr of both buffers remains unchanged.
        memcpy(_buffer, other._buffer, BUFFER_SIZE);
    }

    constexpr RingbufferFinal& operator=(const RingbufferFinal<BUFFER_SIZE>& other)
    {
        memcpy(_buffer, other._buffer, BUFFER_SIZE);
        return *this;
    }
};