Re: [boost] [chrono] Header only library build and boost::system dependency

Subject: Re: [boost] [chrono] Header only library build and boost::system dependency
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2016-05-04 01:17:28

Le 04/05/2016 06:05, Edward Diener a écrit :
> The documentation for chrono says:
>
> "How to Build Boost.Chrono as a Header Only Library?
>
> When BOOST_CHRONO_HEADER_ONLY is defined the lib is header-only.
>
> If in addition BOOST_USE_WINDOWS_H is defined <windows.h> is included, 
> otherwise files in boost/detail/win are used to reduce the impact of 
> including <windows.h>.
>
> However, you will either need to define 
> BOOST_CHRONO_DONT_PROVIDE_HYBRID_ERROR_HANDLING or link with 
> Boost.System. "
>
> So I have:
>
> #define BOOST_CHRONO_HEADER_ONLY
> #define BOOST_CHRONO_DONT_PROVIDE_HYBRID_ERROR_HANDLING
> #include <boost/chrono.hpp>
>
> followed by some code using chrono, and I still get when linking my exe:
>
> gcc.link 
> C:\Programming\VersionControl\modular-boost\build\boost\bin.v2\libs\cxx_dual\test\test_chrono.test\gcc-mingw-5.3\debug\test_chrono.exe
> C:\Programming\VersionControl\modular-boost\build\boost\bin.v2\libs\cxx_dual\test\test_chrono.test\gcc-mingw-5.3\debug\test_chrono.o: 
> In function `_static_initialization_and_destruction_0':
> E:\Programming\VersionControl\modular-boost\libs\cxx_dual\test/../../../boost/system/error_code.hpp:221: 
> undefined reference to `boost::system::generic_category()'
> E:\Programming\VersionControl\modular-boost\libs\cxx_dual\test/../../../boost/system/error_code.hpp:222: 
> undefined reference to `boost::system::generic_category()'
> E:\Programming\VersionControl\modular-boost\libs\cxx_dual\test/../../../boost/system/error_code.hpp:223: 
> undefined reference to `boost::system::system_category()'
> collect2.exe: error: ld returned 1 exit status
>
> Is there a way to use chrono without having to link boost::system ?
>
>
Hi,

Please fill a Trac ticket so that I don't forget to check this.

Coud you try to replace in boost/chrono/detail/system.hpp:

#include <boost/system/error_code.hpp>

with

#if defined BOOST_CHRONO_PROVIDE_HYBRID_ERROR_HANDLING
#include <boost/system/error_code.hpp>
#endif

I will come to you on a week.

Vicente