span>; } </div></div><!-- fragment --><p> This returns true or false (preserve or not preserve, sample or do not sample) at generation <code>generation</code>. Adding a <code>__host__</code> flag is optional, but if done, the function must be defined in CUDA source file (*.cu) or declared/defined header file (*.h, *.hpp, *.cuh, etc...) which is included in a CUDA source file. If no flag added, function can be defined in a regular C/C++ source file (e.g. *.c, *.cpp). Note: run_sim is required to be in a CUDA