Error while doing set_difference: Variable result is not a structure

Question

i had declared a set variable outside a function globally.

std::set s1;
std::set s2;   
std::set interse         


        

Answer 1

std::set_difference(s1.begin(), s1.end(), s2.begin(), s2.end(),std::inserter(_result_, _result_.end()));

Add type parameter in inserter definition:

std::set_difference(s1.begin(), s1.end(), s2.begin(), s2.end(), std::inserter< std::set >(_result_, _result_.end()));