c++ - Where should the user-defined parameters of a framework be ? -

i kind of newbie , creating framework evolve objects in c++ evolutionary algorithm. evolutionary algorithm evolves objects , tests them best solution (for example, evolve weights neural network , test on sample data, in end network has accuracy, without having trained it).

my problem there lots of parameters algorithm (type of selection/crossover/mutation, probabilities each of them...) , since framework, user should able access , modify them.

current solution

for now, created header file parameters.h of form:

// don't change these parameters //mutation type #define flip 1 #define add_connection 2 #define rm_connection 3   // user defined static const int type_of_mutation = flip;  

the user modifies static variables type_of_mutation , mutation function tests value of type_of_mutation , calls right mutation function.

this works well, has few drawbacks:

• when change parameter in header , call "make", no change taken account, have call "make clean" "make". saw, not problem in makefile how building works. if did re-build when change parameter, mean re-compile whole project these parameters used everywhere; not efficient.
• if want run genetic algorithm several times different parameters, have run first time save results, change parameters run second time etc.

other possibilities

i thought taking these parameters arguments of top-level function. problem function take 20 arguments or so, doesn't seem readable...

what mean top-level function now, evolutionary algorithm run doing this:

  populationmanager mypop;    mypop.evolveit(); 

if defined parameters arguments, have like:

  populationmanager mypop;    mypop.evolveit(20,10,5,flip,9,8,2,3,tournament,0,23,4); 

you can see how hellish may define parameters in right order !

conclusion

the frameworks know make build algorithm pre-defined functions, user shouldn't have go through code change parameters 1 one.

it may useful indicate framework used internally, definite set of projects.

any input best way define these parameters welcome !

if options not change use struct this:

 enum class mutationtype {   flip,   addconnection,   removeconnection };  struct options {   // documentation mutation_type.   mutationtype mutation_type = mutationtype::flip;    // documentation integer option.   int integer_option = 10; }; 

and provide constructor takes these options.

options options; options.mutation_type = mutationtype::addconnection; populationmanager population(options); 

c++11 makes easy, because allows specifying defaults options, user needs set options need different default.

also note used enum options, ensures user can use correct values.