C++98 Language Features

Classes and Object-Oriented Programming

C++98 introduced a complete object-oriented system on top of C:

• Class Definition: Encapsulation of data and behavior
• Inheritance: Single inheritance, multiple inheritance, virtual inheritance
• Polymorphism: Virtual functions (virtual), pure virtual functions
• Access Control: public, protected, private
• Abstract Base Classes: Classes containing pure virtual functions cannot be instantiated

Templates

Function templates and class templates are the cornerstones of generic programming:

// Function template
template<typename T>
T max(T a, T b) { return a > b ? a : b; }

// Class template
template<typename T>
class Stack {
    std::vector<T> elems;
public:
    void push(const T& elem);
    T pop();
};

Exception Handling

try {
    // Code that may throw an exception
    throw std::runtime_error("something went wrong");
} catch (const std::exception& e) {
    std::cerr << e.what() << '\n';
} catch (...) {
    // Catch all exceptions
}

Namespaces

namespace MyLib {
    class Widget { /* ... */ };
}

MyLib::Widget w;  // Qualified via namespace when used

Other Features

• RTTI: typeid, dynamic_cast
• const Qualifier: Variables, pointers, references, member functions
• References: Lvalue references (T&)
• Operator Overloading
• new / delete
• static_cast / dynamic_cast / const_cast / reinterpret_cast