Boost库的多重链接

Question

Is there can be a problem like ODR if application link with some libraries of boost and another library that compiled with link with boost?

Example: foo.exe link with boost-*.lib and bar.lib , previously when compiling bar.lib it was link with boost-*.lib too.

Libraries build as Multi-threaded in terms of MSVC.

Answer 1

I had a similar issue with libcURL and OpenSSL with static linking. The libCURL library uses OpenSSL for https download, and needs to link to OpenSSL when compiling it. My observation is:

• If you link libcURL to OpenSSL, then you don't need to link your program to OpenSSL when it uses libCURL
• If you link libcURL to OpenSSL and also link your program to OpenSSL, MSVC will complain that multiple and conflicting implementations exist.

What I recommend is that you try to link to bar.lib without that boost library, and see if it works. If it compiles, you're good without it. If you get an undefined reference error, then you need to link to it. That's the worst case scenario.

Answer 2

Mixing multiple versions of Boost (including header only libraries) in the same process is always a bad idea. Boost provides no API nor ABI guarantees, if two differing versions ever touch one another then expect memory corruption and worse.