"needs to have dll-interface" error when using protobuf with Visual C++ 2017

[John Lilley]

I have installed protobuf 3.5.1 using the "vcpkg" method on Windows.  I can generate code, but when I try to compile I get many errors like:

1>f:\vcpkg\installed\x64-windows\include\google\protobuf\stubs\logging.h(100): warning C4251: 'google::protobuf::internal::LogMessage::message_': class 'std::basic_string<char,std::char_traits<char>,std::allocator<char>>' needs to have dll-interface to be used by clients of class 'google::protobuf::internal::LogMessage'

1>c:\program files (x86)\microsoft visual studio\2017\professional\vc\tools\msvc\14.14.26428\include\xstring(4347): note: see declaration of 'std::basic_string<char,std::char_traits<char>,std::allocator<char>>'

I can use std::string elsewhere in my code without this issue, so I suspect that I need to set some preprocessor flag(s) in my project? 

The Readme says "When compiling your project, make sure to #define PROTOBUF_USE_DLLS".  However, doing so has no effect other than to report a duplicate macro definition warning.

Thanks

john




[John Lilley]

Never mind, I RT'd the FM :-)

john

--
You received this message because you are subscribed to the Google Groups "Protocol Buffers" group.
To unsubscribe from this group and stop receiving emails from it, send an email to protobuf+u...@googlegroups.com.
To post to this group, send email to prot...@googlegroups.com.
Visit this group at https://groups.google.com/group/protobuf.
For more options, visit https://groups.google.com/d/optout.

[Jim Gallogly]

What in the manual did you read. Searching for the same issue.

[Jim Gallogly]

I think you read that its just a warning and everything will be ok and you can ignore it