What is a metaclass in Smalltalk? Why is object initialization simpler in a language with a reference model of variables (as opposed to a value model)? How does a C++ (or Java or C#) compiler tell...

What is a metaclass in Smalltalk? Why is object initialization simpler in a language with a reference model of variables (as opposed to a value model)? How does a C++ (or Java or C#) compiler tell which constructor to use for a given object? How does the answer differ for Eiffel and Smalltalk?