Re: [boost] Library for configuration file parsing

Subject: Re: [boost] Library for configuration file parsing
From: Marsh Ray (marsh_at_[hidden])
Date: 2010-11-29 21:09:21

On 11/29/2010 06:10 PM, Joel de Guzman wrote:
> On 11/30/2010 6:56 AM, Marsh Ray wrote:
>>
>> C++ and Boost are well suited for secure coding because of the support
>> for type safety,
>> automatic cleanup, and overall deterministic execution. But probably
>> nothing will replace
>> the need to understand what's going on under the hood as well as the
>> attacker.
>
> If that is your reasoning then you can't use Boost (nor cpp-netlib
> for that matter).

Yeah. I've met a few developers, hackers, etc working in the data 
security space. I don't think any of them were particularly into of 
template metaprogramming. I doubt any would consider using MPL, for 
instance.

> "The number of "eyes" that can grok" Boost internals "and
> accurately review it are vanishingly small."

That's neither good nor bad, but it does put Boost in a particular place 
in the design space.

Actually, I do think it's good - we need projects that push out the 
corners to expand that space, and that's what I love about Boost. But a 
more typical software project being built by mortal men on a schedule 
usually can't afford the conceptual costs of bringing in more than one 
or maybe two of those corners. As square as this sounds, you've got to 
keep a foothold in the mainstream.

> Yet, anyone claiming to be
> a C++ security expert positioned to review code for "software quality"
> should be able to review any and all sort of C++ code, even the template
> heavy code like MPL.

That's a really good point, but I think on balance I disagree.

Here's why: Someone might know everything there is to know about, say, 
programming in C, but not be qualified to review hard-real-time robotics 
systems written in C (though they would obviously have a lot to 
contribute). So there's a distinction between the language and the 
problem domain and you need to be able to understand both.

Template instantiation is a Turing-complete language and MPL 
specifically seeks to enable programming in it. So I think it's 
reasonable that even an experienced team of C++ practitioners might 
decide that some particular big chunk of metaprogramming wasn't worth 
the conceptual overhead for a particular project.

This stuff has a cost, abstraction isn't free. Witness the threads on 
template error messages. But when it works out, it can be dynamite: STL.

> Spirit is not special. It uses the same template
> metaprogramming techniques that is prevalent in most of Boost libraries.
> There is no black magic there.

Haha, I don't think you'll find many people (outside of this list) who 
don't think it is exactly black magic. :-)

Personally I think it's pretty awesome.

> [I'll try to reply to your Spirit related comments in another post.
> As I see it, your comments there (relating to not being able to
> make it your code work and that JSON is easy to code in C) is totally
> irrelevant.]

All I was trying to say was that I could really use a no-fuss, 
bulletproof JSON facility and Spirit seemed like overkill for this 
simple format.

- Marsh