have a question about Sample Class

[pdycp3]

Sample::Sample(Sample* samples) { _dataset=samples->_dataset; _labels=samples->_labels; _classNum=samples->getClassNum(); _featureNum=samples->getFeatureNum(); _sampleNum=samples->getSampleNum(); _selectedSampleNum=samples->getSelectedSampleNum(); _selectedFeatureNum=samples->getSelectedFeatureNum(); _sampleIndex=samples->getSampleIndex(); _featureIndex=samples->getFeatureIndex(); } Sample::~Sample() { _sampleIndex=NULL; _featureIndex=NULL; } Is it safe to write this way