// Created by Ketan Lalcheta //Taken help from community. Thanks Tsering //https://www.sololearn.com/Discuss/3038425/why-not-able-to-use-initializer-list #include #include using namespace std; template class myClass { public: myClass(size_t N) : m_capacity(N), m_data(new T[m_capacity]) {} ~myClass() { delete[] m_data; } myClass(initializer_list lstData) : m_capacity(lstData.size()), m_data(new T[m_capacity]) { int i = 0; for (auto val : lstData) m_data[i++] = val; } struct myIterator { // changed some names to make them usable by std::iterator_traits since it is needed by std::reverse_iterator using iterator_category = std::random_access_iterator_tag; using difference_type = std::ptrdiff_t; using value_type = T; using pointer = T*; using reference = T&; myIterator(pointer ptr) : m_ptr(ptr) {} pointer operator->() { return m_ptr; } reference operator*() { return *m_ptr; } myIterator& operator++() { ++m_ptr; return *this; } myIterator operator++(int) { myIterator copy = *this; ++(*this); return copy; } myIterator& operator--() { --m_ptr; return *this; } myIterator operator--(int) { myIterator copy = *this; --(*this); return copy; } friend bool operator==(const myIterator& itA, const myIterator& itB) { return itA.m_ptr == itB.m_ptr; } friend bool operator!=(const myIterator& itA, const myIterator& itB) { return itA.m_ptr != itB.m_ptr; } private: pointer m_ptr; }; myIterator begin() { return myIterator(&m_data[0]); } myIterator end() { return myIterator(&m_data[m_capacity]); } using ReverseIterator = std::reverse_iterator< myIterator >; ReverseIterator rbegin() { return ReverseIterator(end()); } ReverseIterator rend() { return ReverseIterator(begin()); } private: size_t m_capacity; T* m_data; }; int main() { //myClass obj(5); myClass obj({ 5,7,9,11,13,15,61 }); for (auto itr = obj.begin(); itr != obj.end(); ++itr) { cout << *itr << " "; } cout << endl; for (auto itr = obj.rbegin(); itr != obj.rend(); ++itr) { cout << *itr << " "; } cout << endl; fill(obj.begin(),obj.end(),5); for (auto itr = obj.begin(); itr != obj.end(); ++itr) { cout << *itr << " "; } cout << endl; return 0; }

Q&A: reverse iterator