RTTI in Cross-Platform Development

1// Check if RTTI is enabled
2#if defined(__GXX_RTTI) || defined(_CPPRTTI)
3  std::cout << "RTTI is enabled\n";
4#else
5  #error "RTTI is required for this code"
6#endif

1#include <string>
2#include <typeinfo>
3
4template <typename T>
5std::string getTypeName() {
6#ifdef _MSC_VER
7  return typeid(T).name();  // Visual Studio
8#elif defined(__GNUG__)
9  int status;
10  char* demangled = abi::__cxa_demangle(
11    typeid(T).name(), 0, 0, &status);
12  std::string result(demangled);
13  free(demangled);
14  return result;  // GCC/Clang
15#else
16  return typeid(T).name();  // Other compilers
17#endif
18}

1#include <iostream>
2#include <typeinfo>
3
4void printType(const Monster* monster) {
5  try {
6    std::cout << "Type: " << typeid(*monster).name();
7  } catch (const std::bad_typeid& e) {
8    std::cerr << "Error: " << e.what();
9  }
10}

1Monster* monster = getMonster();
2
3// Dynamic casting a reference
4try {
5  Dragon& dragon = dynamic_cast<Dragon&>(*monster);
6  // Dragon-specific code
7} catch (const std::bad_cast&) {
8  std::cerr << "Not a Dragon\n";
9}
10
11// Dynamic casting a pointer
12Dragon* dragon = dynamic_cast<Dragon*>(monster);
13if (dragon) {
14  // Dragon-specific code
15} else {
16  std::cerr << "Not a Dragon\n";
17}

1// Compile-time alternative to dynamic_cast
2template<typename Base, typename Derived>
3Derived* fast_cast(Base* base) {
4  static_assert(
5    std::is_base_of<Base, Derived>::value,
6    "Invalid cast"
7  );
8  return static_cast<Derived*>(base);
9}

1// Avoid this:
2if (typeid(long) == typeid(long long)) {
3  // This may vary across platforms
4}
5
6// Prefer this:
7if (sizeof(long) == sizeof(long long)) {
8  // This is more reliable
9}

1void testRTTI() {
2  Monster* monster = new Dragon();
3  assert(typeid(*monster) == typeid(Dragon));
4  assert(dynamic_cast<Dragon*>(monster) != nullptr);
5  delete monster;
6}

1/**
2 * @brief Get the type name of the object
3 * @note
4 *   On Windows, this returns the decorated name.
5 *   On Unix, this returns the demangled name.
6 */
7std::string getObjectTypeName() const {
8  return typeid(*this).name();
9}

1enum class MonsterType { Base, Dragon, Goblin };
2
3class Monster {
4 public:
5  virtual MonsterType getType() const {
6    return MonsterType::Base;
7  }
8};
9
10class Dragon : public Monster {
11 public:
12  MonsterType getType() const override {
13    return MonsterType::Dragon;
14  }
15};