#include #include #include #include #include using namespace std; class clsTest { public: clsTest(int a) : m_intA(a){} //required for set and map as default comparator is less bool operator<(const clsTest& obj)const { return m_intA < obj.m_intA; } //required for set and map for greater comparator bool operator>(const clsTest& obj)const { return m_intA > obj.m_intA; } //required for collision check in case of unordered_map or unordered_set bool operator==(const clsTest& obj)const { return m_intA == obj.m_intA; } int m_intA; }; //hash function for unordered_set or unordered_map to enable hashing //1. This is overiding of hash class for our own class inside std namespace //2. If this is given, unordered_set or unordered_map declaration don't need extra argument //3. For example, TrialUnorderedSet namespace std { template<> struct hash { size_t operator()(const clsTest& obj)const { return obj.m_intA; } }; } //hash function for unordered_set or unordered_map to enable hashing //1. This is example of custom hash class //2. If this is given, unordered_set or unordered_map declaration need extra argument //3. For example, TrialUnorderedMap struct Myhash { size_t operator()(const clsTest& obj)const { return obj.m_intA; } }; void TrialSet() { set data; data.insert(clsTest(5)); data.insert(clsTest(1)); data.insert(clsTest(4)); data.insert(clsTest(3)); data.insert(clsTest(2)); for (auto& elem : data) { cout << elem.m_intA << " "; } cout << endl << endl; } void TrialMap() { map data; data.insert({clsTest(5),"Index 0"}); data.insert({clsTest(1),"Index 1"}); data.insert({clsTest(4),"Index 2"}); data.insert({clsTest(3),"Index 3"}); data.insert({clsTest(2),"Index 4"}); for (auto& elem : data) { cout << elem.first.m_intA << " -> " << elem.second << " , "; } cout << endl << endl; } void TrialSet_Greater() { set> data; data.insert(clsTest(5)); data.insert(clsTest(1)); data.insert(clsTest(4)); data.insert(clsTest(3)); data.insert(clsTest(2)); for (auto& elem : data) { cout << elem.m_intA << " "; } cout << endl << endl; } void TrialMap_Greater() { map> data; data.insert({ clsTest(5),"Index 0" }); data.insert({ clsTest(1),"Index 1" }); data.insert({ clsTest(4),"Index 2" }); data.insert({ clsTest(3),"Index 3" }); data.insert({ clsTest(2),"Index 4" }); for (auto& elem : data) { cout << elem.first.m_intA << " -> " << elem.second << " , "; } cout << endl << endl; } void TrialUnorderedSet() { unordered_set data; data.insert(clsTest(5)); data.insert(clsTest(1)); data.insert(clsTest(4)); data.insert(clsTest(3)); data.insert(clsTest(2)); for (auto& elem : data) { cout << elem.m_intA << " "; } cout << endl << endl; } void TrialUnorderedMap() { unordered_map data; data.insert({ clsTest(5),"Index 0" }); data.insert({ clsTest(1),"Index 1" }); data.insert({ clsTest(4),"Index 2" }); data.insert({ clsTest(3),"Index 3" }); data.insert({ clsTest(2),"Index 4" }); for (auto& elem : data) { cout << elem.first.m_intA << " -> " << elem.second << " , "; } cout << endl << endl; } int main() { TrialSet(); TrialMap(); TrialSet_Greater(); TrialMap_Greater(); TrialUnorderedSet(); TrialUnorderedMap(); return 0; }

CustomClass_Map_Set_UnorderedMap_UnorderedSet