>     Roger,

>     This is true for the user of the class, not for the author. I mean 
> the methods operating on the private part. This is typical of the C++ 
> philosophy: make everything possible but by hand crafting and at the 
> cost of possible errors an/or unreadable source.

>     Imagine you want to implement an integer with an allowed range [7, 
> 107], you will need to embed it inside a class and provide a setter 
> which  raises an exception if the argument is not within the range. In 
> Ada, you declare your type with its range and the compiler does the 
> check for you: everywhere it cannot determine at compile-time if the 
> value is in the range, it will silently insert the necessary 
> instructions to verify.

>     Didier