Re: [Boost-users] FindBoost.cmake does not check for include headers

Subject: Re: [Boost-users] FindBoost.cmake does not check for include headers
From: Roger Leigh (rleigh_at_[hidden])
Date: 2016-04-13 14:24:23

On 13/04/2016 16:14, j.wuttke wrote:
> As per cmake 3.5.1, FindBoost.cmake does not check for include headers.
> Therefore it will give false positives
> - if a Boost project that only consists of a header file is not installed
> - if only a libboost* is installed, but not the headers from the
> corresponding
>    *-dev package.
>
> I raised this issue long ago on the cmake bug tracker, and recently again
> on the cmake mailing list, but got no response. Would perhaps somebody
> from the Boost community volunteer to look into this issue? Or has already
> looked into it and could tell us what the problem is?

I'm not sure of the historical reasons, but I can state that the reason 
we don't check for individual component headers is because that would 
require maintaining a static mapping of every component to header(s) 
provided by that component *for each version of boost*.  This would be 
exceedingly hard to do; it's already at the limits of the reasonable 
and/or possible maintaining the autogenerated dependency information.

That said, if there's any obvious header present in every released 
version of boost which is uncondititionally present for every boost 
build, I don't see why we couldn't add that to check for some basic 
level of availability.  Candidates include:

boost/any.hpp
boost/array.hpp
boost/bind.hpp
boost/config/abi_prefix.hpp
boost/config/abi_suffix.hpp
boost/config/auto_link.hpp
boost/cstdint.hpp
boost/limits.hpp
boost/mem_fn.hpp
boost/operators.hpp
boost/optional.hpp
boost/preprocessor.hpp
boost/rational.hpp
boost/ref.hpp
boost/scoped_array.hpp
boost/scoped_ptr.hpp
boost/shared_ptr.hpp
boost/type_traits.hpp
boost/version.hpp

These are in every version from 1.33 to 1.60.  We can test some or 
several of these; we need to be sure they won't be removed in a future 
release though.  boost/config/auto_link.hpp is a safe bet, as is 
boost/version.hpp.  Most of the above most likely.

Regards,
Roger