boost crowd.

[so]

On Mon, 28 Nov 2011 15:52:51 +0200, so <so at so.so> wrote:

> Now how do you know you have a "Lib", and it implements "hello", what  
> rule enforces that?
> If this is all it does, you are overlooking the most important point of  
> header files.

It was obscure.
A header enforces its contents for both library writer and library user.
If library writer needs a change in header. Both writer and the user needs  
to change their code.
For the second part if library writer changes anything with  
"implementation", that would not affect the user.
In your case it does, because there is no distinction between  
specification and implementation, every implementation is the new spec.