Re: Boost 1.76 beta - linking error when including Boost

From: Luigi Ballabio (luigi.ballabio_at_[hidden])
Date: 2021-03-24 13:46:37

Hello, I have a minimal example now.  The program:
------
#include <boost/math/special_functions/atanh.hpp>

int main() {
    auto x = boost::math::atanh(1.0);
    return int(x);
}
------
fails to link in an Ubuntu 20.10 Docker image with g++ 10.2.0 if using
Boost 1.76.0.beta1.  It links with 1.75.0, or with the beta if I also add
#include <boost/math/special_functions/fpclassify.hpp>

Thanks,
    Luigi

On Wed, Mar 24, 2021 at 8:25 AM Luigi Ballabio <luigi.ballabio_at_[hidden]>
wrote:

> Hello,
>     I'm afraid I don't have a minimal example yet, but I thought I'd give
> you a heads-up in case it rings a bell.
>
> I've been trying the Boost 1.76 beta to build a library I'm maintaining.
> The library builds, but when I link it to an executable I'm getting an
> "undefined reference to `bool boost::math::isnan<long double>(long
> double)".  Everything works with 1.75 and earlier.  My code is not using
> boost::math::isnan directly, so I'm guessing some other included boost
> component is forward-declaring it or doing something similar?
>
> The linking error disappears if I
> include <boost/math/special_functions/fpclassify.hpp> in a config file that
> is included by every file in the library.  Today I'll try to pinpoint the
> problem by removing it there and including it before specific boost headers
> in the source files, but as I said, I'm posting this in case someone
> already has an idea about the underlying issue.
>
> Thanks,
>     Luigi
>
>