29     float start_temperature;
 
   30     std::function<float(
float)> anneal;
 
   32     cooling(
unsigned iterations, 
float start_temperature, std::function<
float(
float)> anneal)
 
   33             : iterations(iterations)
 
   34             , start_temperature(start_temperature)
 
   35             , anneal(std::move(anneal)) {}