In file included from main.cpp:16:0:
set.h: In constructor 'Set::Set(const std::vector<long int>&)':
set.h:24:31: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
         for (int64_t i = 0; i < v.size(); i++) {
                             ~~^~~~~~~~~~
set.h: In member function 'Set Set::Union(const Set&) const':
set.h:50:31: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
         for (int64_t i = 0; i < this->set.size(); i++) {
                             ~~^~~~~~~~~~~~~~~~~~
set.h:53:31: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
         for (int64_t j = 0; j < other.set.size(); j++) {
                             ~~^~~~~~~~~~~~~~~~~~
set.h: In member function 'Set Set::Intersection(const Set&) const':
set.h:61:31: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
         for (int64_t i = 0; i < other.set.size(); i++) {
                             ~~^~~~~~~~~~~~~~~~~~
set.h: In member function 'Set Set::Difference(const Set&) const':
set.h:71:31: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
         for (int64_t i = 0; i < this->set.size(); i++) {
                             ~~^~~~~~~~~~~~~~~~~~
set.h: In member function 'Set Set::SymmetricDifference(const Set&) const':
set.h:82:47: error: no matching function for call to 'Set::Difference(const std::vector<long int>&) const'
         s = s.Union(other.Difference(this->set));
                                               ^
set.h:69:9: note: candidate: Set Set::Difference(const Set&) const
     Set Difference(const Set& other) const {
         ^~~~~~~~~~
set.h:69:9: note:   no known conversion for argument 1 from 'const std::vector<long int>' to 'const Set&'
cc1plus: all warnings being treated as errors