Re: beast-0.7.4 issues with g++-4.5

[Tim Janik <tim janik lanedo com>]

On Tue, 19 Apr 2011, Stefan Westerfeld wrote:

> On Sat, Apr 09, 2011 at 09:09:23PM +0200, Stefan Westerfeld wrote:

> > CXX    birnetutils.lo
> > birnetutils.cc:253:111: error: array bound is not an integer constant before ']' token
> > birnetutils.cc:254:111: error: array bound is not an integer constant before ']' token
> > birnetutils.cc:255:109: error: array bound is not an integer constant before ']' token
>
> I investigated the issue a little further. First of all, I tried using BOOST_STATIC_ASSERT
> instead of BIRNET_STATIC_ASSERT, just to see if our static assertion facility needs to
> be fixed. However, BOOST_STATIC_ASSERT behaves the same way like BIRNET_STATIC_ASSERT:
> it fails on those expressions involving DBL_MIN/DBL_MAX/DBL_EPSILON on g++-4.5, and
> succeeds with g++-4.4. There are IMHO several ways to fix compilation with g++-4.5.

> 4) Move assertions to runtime checks at startup. For instance with global
> constructors, we could keep the test in the same file, but the constructor
> would do the assertions and prevent starting BEAST if the test does not work.
>
> 5) We could disable these static assertions altogether (or conditionally for
> g++ >= 4.5.0) , but I think thats not such a good option, as they were designed
> to prevent problems down the road, so I'm not considering this at the moment.
>
> As there are multiple approaches on how to fix the issue, I'd like some
> guidance here as on which approach to take. I can make a patch/merge request
> for approach 2, 3 or 4, as soon as the decision on which route to take is made.

I'd favor something similar to the effect of 4, but I really think the compiler
needs fixing here. I.e. we should just hold the horses here and see how the GCC/Boost
teams are sorting it out. Both have more resources and a wider user base than Beast,
so being patient will just provide a solution automatically.
Until then, only GCC-4.4 is supported by Beast/Rapicorn, which is fine.

>   Cu... Stefan

Yours sincerely,
Tim Janik

---
http://lanedo.com/~timj/ - Founder and CEO of Lanedo GmbH.
Free software author and contributor on various projects.