do we need to recompile libraries with c++11?

Question

This is a very uninformed question, but:

I would like to start using C++11. Can I continue to use my large collection of libraries which were compiled with my old gcc 4.2.1 compiler or do I need to recompile them all with a new compiler? I would think (or hope) the answer is no, but I am only a dabbler.

So that I may have at least part of my ignorance removed, can you explain why in either case?

Thanks

Answer 1

Yes, you should.

The weaker reason is not binary compatibility, the problem is about expectations. A C++11 enabled compiler will expect a number of features to be available (move constructors among them) and use them when appropriate. And that's only scratching the tip of the iceberg, there are several other incompatibilities (auto, 0 and its interaction with pointers, ...).

It means that any inline method in a header may suddenly be interpreted differently, in light of the C++11 Standard.

The stronger reason is that each version of the compiler comes with its own Standard Library implementation. You don't really want start mixing various versions around and especially not when they have undergone such major changes (once again, rvalue references...).

Believe me, it's simpler to recompile now rather than having that nagging thought that each bug that appear may be due to an incompatibility between old and new libraries...