inline int unpack( vector_float const& real_float_coefficient,
		  vector_complex_float& complex_coefficient ){
	size_t n = std::max( real_float_coefficient.size(), complex_coefficient.size() );
	return gsl_fft_real_float_unpack( real_float_coefficient.data(), complex_coefficient.data(),
					  1, n ); }
      inline int unpack( vector_float const& real_coefficient, vector_complex_float& complex_coefficient,
			 size_t const stride ){
	size_t n = std::max( real_coefficient.size(), complex_coefficient.size() );
	return gsl_fft_halfcomplex_float_unpack( real_coefficient.data(), complex_coefficient.data(),
					   stride, n ); }