id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
12974	Log and Asio without defined _WIN32_WINNT	sobolevsv@…	chris_kohlhoff	"platform: Win10, VC14, boost 1.64

Using Log and Asio simultaneously cause link errors depending on order of includes.

if _WIN32_WINNT not defined and there are several translation units, most of it use only Log and some use both Log and Asio I get link error

if Log includes come first followed by Asio, building complete successfull[[BR]]
for example

{{{
#include <boost/log/common.hpp>
#include <boost/log/sources/severity_channel_logger.hpp>
#include <boost/asio.hpp>
}}}


but if Asio include comes before Log includes[[BR]]
for example

{{{
#include <boost/asio.hpp>
#include <boost/log/common.hpp>
#include <boost/log/sources/severity_channel_logger.hpp>
}}}


I get link error:
LNK2038: mismatch detected for 'boost_log_abi': value 'v2s_mt_nt5' doesn't match value 'v2s_mt_nt6' in gtclient.obj

this message generated by #pragma detect_mismatch in boost\log\detail\config.hpp :
{{{
#if defined(BOOST_LOG_HAS_PRAGMA_DETECT_MISMATCH)
#pragma detect_mismatch(""boost_log_abi"", BOOST_PP_STRINGIZE(BOOST_LOG_VERSION_NAMESPACE))
#endif
}}}


it happend becase Log and Asio use different macros to define target Windows version.[[BR]]

Log use BOOST_USE_WINAPI_VERSION[[BR]]
but Asio use _WIN32_WINNT

in 
\boost\asio\detail\config.hpp [[BR]]
Asio checks if _WIN32_WINNT defined.
if not, it defines it
{{{
#  define _WIN32_WINNT 0x0501
}}}



BOOST_USE_WINAPI_VERSION defined in
boost\detail\winapi\config.hpp 

it depends on _WIN32_WINNT and _MSC_VER


{{{
#if !defined(BOOST_USE_WINAPI_VERSION)
#if defined(_WIN32_WINNT)
#define BOOST_USE_WINAPI_VERSION _WIN32_WINNT
#elif defined(WINVER)
#define BOOST_USE_WINAPI_VERSION WINVER
#else
// By default use Windows Vista API on compilers that support it and XP on the others
#if (defined(_MSC_VER) && _MSC_VER < 1500) || defined(BOOST_WINAPI_IS_MINGW)
#define BOOST_USE_WINAPI_VERSION BOOST_WINAPI_VERSION_WINXP
#else
#define BOOST_USE_WINAPI_VERSION BOOST_WINAPI_VERSION_WIN6
#endif
#endif
#endif
}}}


I think this error appeared in boost 1.60 when Log started using BOOST_USE_WINAPI_VERSION
http://www.boost.org/users/history/version_1_60_0.html

if I define _WIN32_WINNT=0x0A00 in compiler option, there are no link error with any includes ordering."	Bugs	new	To Be Determined	asio	Boost 1.64.0	Problem		Win10 VC14	sobolevsv@…