#include #include #include #include class CString { private: char *cstring; public: CString(const char* s = "") : cstring{nullptr} { if(s) { std::cout << "Inside constructor if\n"; std::size_t n = std::strlen(s) + 1; cstring = new char[n]; std::memcpy(cstring, s, n); } else { std::cout << "Inside constructor else\n"; } } ~CString() { delete[] cstring; } CString(const CString& other) : CString(other.cstring) // Copy constructor. { std::cout << "Copy constructor\n"; } CString(CString&& other) noexcept // Move constructor. // Assign nullptr to other.cstring, and the old value is assigned // to cstring. : cstring(std::exchange(other.cstring, nullptr)) { std::cout << "Move constructor\n"; } CString& operator=(const CString& other) { std::cout << "Copy assignment" << '\n'; if(this == &other) return *this; // Allocate memory and copy its data. char* new_string = new char[std::strlen(other.cstring) + 1]; std::copy(other.cstring, other.cstring + std::strlen(other.cstring) + 1, new_string); // Deallocate old memory. delete[] cstring; // Assign the new memory to the object. cstring = new_string; return *this; } CString& operator=(CString&& other) noexcept { std::cout << "Move copy\n"; std::swap(cstring, other.cstring); return *this; } operator const char*() const { return cstring; } }; int main() { CString cstring {"jose jose"}; std::cout << "cstring: " << cstring << '\n'; CString cstring2 {cstring}; std::cout << "cstring2: " << cstring2 << '\n'; // Comment this 3 lines and now 77-80 will show in the console. CString cstring3 = std::move(cstring2); std::cout << "cstring3: " << cstring3 << '\n'; std::cout << "cstring2: " << cstring2 << '\n'; // This lines aren't executed if 73-75 aren't commented/deleted. CString cstring4 {"que pedo"}; CString cstring5; cstring5 = cstring4; std::cout << "cstring5 copied from cstring4: " << cstring5 << '\n'; return 0; }

move constructor, move copy