Re: What's wrong with C++?

["Yannick Duchêne (Hibou57)" <yannick_duchene@yahoo.fr>]

Le Tue, 04 Oct 2011 22:51:29 +0200, Yannick Duchêne (Hibou57)  
<yannick_duchene@yahoo.fr> a écrit:
> Here is an easy to read interesting answer to that question, from a C++  
> user, reporting about a C++ conference he attended to.
>
> http://cpptruths.blogspot.com/2005/10/whats-wrong-with-c.html

Quoted from a comment in the above link

> "One of the big issues was the extreme difficulty of parsing C++."
>
> It is ___provably___ impossible to write a correct C++ parser which
> will complete compilation with either success of failure because the
> C++ template system is Turing complete. This means that code generation
> is based on a turing complete program. Code generation in C++ isn't
> based on a program description, but an actual turing complete program.
>
> As such, it is subject to the halting problem. Therefore, it is
> unknowable whether a compilation will complete, and unknowable if
> you are looking at a valid C++ program.

So OK, it is formally proved that is not even sure a given C++ source file  
can really be compiled or not. That's big, ouch.

That achieve to prove that along with the domain troubles and  
difficulties, you are also in as great troubles with the source it self.

May be C++ would need to go beyond of Ada SPARK or Ada design by contract  
(tm), and add stuff to prove a C++ source is correct and can be compiled,  
before any attempt to prove what it will compiled is correct (oops).


-- 
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