C++ frequently questioned answers

[TomD]

Walter Bright Wrote:

> An interesting and sometimes amusing read:
> 
> http://yosefk.com/c++fqa/
The chapter about iostream tells me why I do not like Tango's IO :-)

But I wonder if the following is also true for D:
----snip---
[10.1] What's the deal with constructors?

FAQ: A constructor initializes an object given a chunk of memory having arbitrary (undefined) state, the way "init functions" do. It may acquire resource like memory, files, etc. "Ctor" is a common abbreviation.

FQA: That's right - constructors initialize objects. In particular, constructors don't allocate the chunk of memory used for storing the object. This is done by the code calling a constructor.

The compiler thus has to know the size of a memory chunk needed to store an object of a class (this is the value substituted for sizeof(MyClass)) at each point where the class is used. That means knowing all members (public & private). This is a key reason why changing the private parts of a C++ class definition requires recompilation of all calling code, effectively making the private members a part of the public interface. 

---snap---

Given the compilation speed of DMD, it does not bother me, but still, he
has a point here.

Ciao
Tom