Linking dynamically to boost::locale::info class on Windows fails when auto-linking is disabled

[anonymous]

There appears to be a name-mangling issue in boost::locale::info related to a public static member variable of type std::locale::id, only when linking to the DLL on Windows. When using auto-linking, there is no problem.

Setup

Boost 1.61 (tested on both pre-built and from-source libraries), Windows 10 x64, MSVC 2015 (cl 19.00.24213.1), using x64 compiler.

Code

bugtest.cc

#include <boost/locale.hpp>
#include <iostream>

int main()
{
    std::locale::global(boost::locale::generator().generate("en_US.UTF-8"));
    std::cout << std::use_facet<boost::locale::info>(std::locale()).name() << std::endl;
}

Compiler Command

cl.exe
-IC:\Boost\include\boost-1_61
-DBOOST_ALL_NO_LIB
-EHsc
-O2
bugtest.cc
-link
-libpath:c:\Boost\lib
boost_locale-vc140-mt-1_61.lib

Linker Failure

bugtest.obj : error LNK2019: unresolved external symbol "public: static class std::locale::id boost::locale::info::id" (?id@info@locale@boost@@2V02std@@A) referenced in function "class boost::locale::info const & cdecl std::use_facet<class boost::locale::info>(class std::locale const &)" (??$use_facet@Vinfo@locale@boost@@@std@@YAAEBVinfo@locale@boost@@AEBV20@@Z) bugtest.exe : fatal error LNK1120: 1 unresolved externals

Workaround

Force dllimport attribute

cl.exe
-IC:\Boost\include\boost-1_61
-DBOOST_LOCALE_DECL=__declspec(dllimport)
-DBOOST_ALL_NO_LIB
-EHsc
-O2
bugtest.cc
-link
-libpath:c:\Boost\lib
boost_locale-vc140-mt-1_61.lib

[Artyom Beilis]

You need to add BOOST_ALL_DYN_LINK or BOOST_LOCALE_DYN_LINK definition for your windows projects when linking with DLLs so dllimport will be defined properly.

It is general rule for all boost libraries.

[anonymous]

That's fine, but then the documentation should reflect that turning off auto-linking for DLLs on Windows is an unsupported option. I would expect it to work if linking to the correct import library.