Visual Studio 15 __imp___iob, __imp___pctype, __imp___mb_cur_max

I encountered the same problem (library compiled with static CRT instead of CRT in DLL) and I managed to make it work by changing the two following parameters in Project Properties:

• Linker > Input > Ignore specific default libraries: libc.lib
• C/C++ > Code Generation > Runtime Library: Multi-threaded Debug (/MTd)

If that's not enough, there's more at following page: https://social.msdn.microsoft.com/Forums/en-US/841e5723-bce4-4340-b7b3-027dcdf90f00/

The libraries were compiled against an old version of the CRT. The unresolved symbols you get are internal symbols of the CRT that are present in the compiled library. You have to recompile the library against the VS2015 CRT (the Universal CRT). But I'm not sure if MinGW supports this.

If you can't do that, you have to continue to use the VS2013 compiler. (You can use the VS2015 IDE, by setting the toolset to vs2013 in the project options. But you'll still be limited to the C++ features the 2013 compiler supports.)