How to mock delegate constructors?

What are advantages and disadvantages of Java-like constructors compared to Ruby-like constructors?

• As you know, in Java constructors are defined using a special form that while similar to methods, they are totally different in that they don't have any return values. In Ruby, on the other hand, constructors are methods with a special name (i.e. initialize). What are advantages and disadvantages of this two approaches of implementing constructors in a programming language?

• Answer:

  To some extent, it's all just a matter of what is consistant with the language. However, one potential advantage of the Ruby style constructors is the decoupling of construction from allocation (which is why you create an instance of class Foo with 'Foo.new()', not 'Foo.initialize()').  Honestly, they are better thought of as initializers rather than constructors (hence the method name 'initialize'). But then, sometimes there is a middle ground.  For example, D has true constructors like in C++ et al, but always named 'this' (as opposed to the Java/C++/C# practise of naming the constructor after the class); and are still separated from allocation, which can be customized either by writing custom allocator into the class (magic method 'new') or by using the standard function template 'emplace' to instantiate an object into a user provided memory block. The only really clear cut case, is the disadvantage of Java/C++/C# style constructors: repeating the class name.  This is yet one more place you have to edit if the name ever changes, and yet one more opportunity for a silly typing mistake to leave you head-scratching for a while when the compiler calls you stupid.  Of course the refactoring tools of a decent IDE cover for this.