Managed C++ | Steven Engelhardt

Managed Wrappers and Hidden Interdependencies

Let’s say you have the following unmanaged code:

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#pragma unmanaged

class Stream { ... }; // Conceptual stream class

class StreamWriter
{
public:
    StreamWriter(Stream* pStream) : m_pStream(pStream) {}
    ~StreamWriter() { /* Use m_pStream in some way */ }

    ...

private:
    Stream* m_pStream;
};

void f()
{
    Stream stream;
    StreamWriter streamWriter(&stream);

    // Use streamWriter
    // streamWriter is destroyed
    // stream is destroyed
}

Note that StreamWriter’s destructor uses m_pStream (perhaps by flushing the stream). This means that the order of destruction is important — StreamWriter must be destroyed before its underlying Stream is.