Method set_input_precallback

src/tests/fftw_transform.h:460–475

	}

	void set_input_precallback()
	{
		//precallback user data
		buffer<T> userdata( 	input.number_of_dimensions(),
					input.lengths(),
					input.strides(),
					input.batch_size(),
					input.distance(),
					layout::real ,
					CLFFT_INPLACE
					);
		
		userdata.set_all_to_random_data(_lengths[0], 10);
		
		input *= userdata;
	}

	void set_input_precallback_special()
	{