In the release notes of version 1.50.0 of the Boost libraries I noted two breaking changes (see here):
#6266 Breaking change: thread destructor should call terminate if joinable.
#6269 Breaking change: thread move assignment should call terminate if joinable.
What does this mean for my existing projects currently using Boost 1.49.0? Do I have to change anything? If yes, what do I have to change exactly? And what happens if I forget to modify one of my existing projects? Will I get compile time errors (I hope so) or will I get nasty and hard-to-find runtime problems (I absolutely don’t hope so)?
When it says “Breaking change”, it means, “Your program is broken if you depend on behaviour which was previously X, but is now Y”.
For the given two changes, it means that if you rely on the destructor or move assignment calling
join()(ordetach()), which I believe was the previous behaviour, your program must now explicitlyjoin()ordetach()or meet your friendstd::terminate(). It’s not a compile-time error, but nor is it unpredictable run-time behaviour- you’ll get a nice clean crash leading right back toboost::thread‘s destructor, which is the cause of the problem.