Re: [boost] Use of third-party libraries

Subject: Re: [boost] Use of third-party libraries
From: Michael Shepanski (mps_at_[hidden])
Date: 2014-07-24 03:11:07

On 23/07/2014 9:31 PM, Andrey Semashev wrote:
> The library build scripts should perform auto-detection checks at
> build time. I have something like this in Boost.Log, although I test
> whether the compiler supports SSE/AVX and whether Message Compiler is
> available. But the approach should be similar - you attempt to compile
> a test application and set up build macros or select the actual
> sources to build from.

So let's say I'm trying to decide whether libpq is installed. Your 
suggestion is that I "attempt to compile a test application". So I would 
have to tell the compiler the location of libpq's incude directory (and 
if I attempt to link then I have to tell the linker the location of the 
libpq binary). Now, at the moment, the only way I know these locations 
is from the constants "libpq_include_dir" and "libpq_lib_dir", defined 
in user-config.jam (see 
http://quince-lib.com/preparation/configuring_boost_build.html). So I 
might as well test those constants directly, no? Or should I be 
determining the "installed" locations of those things by some other means?

> You can also take a look at Boost.IOStreams which detect if bzip2 and
> zlib are available.

Its Jamfile.v2 says:

     # The biggest trick in this Jamfile is to link to zlib and bzip2 when
     # needed. To configure that, a number of variables are used, which must
     # be set by user with 'path-constant' either in Boost's root 
Jamfile, or
     # in user-config.jam.

> Boost.Thread also contains some auto-detection checks, I think.

Its Jamfile.v2 says:

     # You need to provide the include path and lib path in the variables
     # PTW32_INCLUDE and PTW32_LIB respectively. You can specify these
     # paths in site-config.jam, user-config.jam or in the environment.

I'm thinking that the only auto-detection I need is inspection of bjam 
constants.

--- Michael