FastText wrapper class

FastText.cs

public delegate bool WordCallback(string word, Single score);

class FastText : IDisposable
{
    private IntPtr ft = IntPtr.Zero;
    private WordCallback c = null;

    private void FastTextCheck(bool result)
    {
        if (!result)
            throw new Win32Exception(Marshal.GetLastWin32Error());
    }
	
#region IDisposable Support
    protected virtual void Dispose(bool disposing)
    {
        if (disposing)
        {
        }
        if (ft != IntPtr.Zero)
        {
            FastTextWrapper.fasttext_release(ft);
            ft = IntPtr.Zero;
        }
    }

    public FastText() {
        FastTextCheck(FastTextWrapper.fasttext_new(out ft));
    }

    ~FastText() {
        Dispose(false);
    }

    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }
#endregion

    public bool NN2Callback(StringBuilder word, Single score, IntPtr data)
    {
        return c(word.ToString(), score);
    }

    public void NN2(IntPtr vectors, string[] positive, string[] negative, int count, WordCallback callback)
    {
        c = callback;
        try
        {
            FastTextCheck(FastTextWrapper.fasttext_nn2(ft, vectors, positive, negative, count, new FastTextWrapper.FastTextNNCallback(NN2Callback), IntPtr.Zero));
        }
        finally
        {
            c = null;
        }
    }
}