yaml-cpp: Unable to use yaml-cpp with MSVC 2015 with BUILD_SHARED_LIBS

Hi,

I’m compiling yaml-cpp from source with MSVC 2015, in the RelWithDebInfo x64 configuration, with BUILD_SHARED_LIBS=ON specified. The code fails to link due to lack of YAML_CPP_API on classes in exceptions.h:

6>load_node_test.obj : error LNK2019: unresolved external symbol "public: virtual __cdecl YAML::Exception::~Exception(void)" (??1Exception@YAML@@UEAA@XZ) referenced in function "public: virtual void * __cdecl YAML::Exception::`scalar deleting destructor'(unsigned int)" (??_GException@YAML@@UEAAPEAXI@Z)
6>node_spec_test.obj : error LNK2001: unresolved external symbol "public: virtual __cdecl YAML::Exception::~Exception(void)" (??1Exception@YAML@@UEAA@XZ)

and several more. These are errors from the run-tests project, but my project gives the same. Now, I can solve this for all the non-template classes quite easily, but I also get a lot of “xxx needs to have dll-interface to be used by client of class yyy” warnings. And these warnings result in linkage erros in my project:

1>Parameter.obj : error LNK2001: unresolved external symbol "public: static class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > YAML::detail::node_data::empty_scalar" (?empty_scalar@node_data@detail@YAML@@2V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@A)
1>C:\Documents\src\Mars Initiative\mi-build\Output\entities.dll : fatal error LNK1120: 1 unresolved externals

empty_scalar is a static std::string in node_data, and the dll does not export std::string. I have 600+ “dll-interface” warnings, so I guess the problem is pretty broad. I guess you’re familiar with the issue, but just to make sure we’re on the same page, I’m talking about this problem: https://support.microsoft.com/en-us/help/168958/how-to-export-an-instantiation-of-a-standard-template-library-stl-class-and-a-class-that-contains-a-data-member-that-is-an-stl-object

How would you advise to proceed? 😃 Am I doing something wrong?