Objects that stand for other objects are often called proxy objects (or surrogates), and the classes that give rise to proxy objects are often called proxy classes, which is useful for implementing multidimensional arrays, differentiating lvalue/rvalue, and suppressing implicit conversions.

Reference counting is technique that allows multiple objects with the same value to share a sinple representation of that value.

Smart pointers are designed to look, act, and feel like built-in pointers, but to offer greater functionality.

Techniques for requiring or prohibiting heap-based objects

Combining object-counting technique with the pseudo-constructors, we can limit the number of objects of a class.