extern in macro

[wolle]

I'm using a library that provides some macros that adds overrided methods, etc.

The library provides the macros but do you have to use them?

If the macros change you will get compiler errors no matter what so you can as well not use them making your own code better.

[TubularX]

if your cpp includes some headers containing a clashing name at global scope ...

OK, I see what you mean now. I consider it low risk, but indeed, in that case I'll need to rename my class. It's not exported, though, so no big deal.

Still, I think it will be convenient to have it in the same namespace as the rest of my code.

"If the macros change you will get compiler errors no matter what"

There's no such guarantee.

[wolle]

There's no such guarantee.

You could use an assertion which fails when there has been a change to a macro. If the macros are expanded in byte arrays the CRC sums of the byte arrays will be fingerprints of the macros (or the whole byte arrays could serve as fingerprints for that matter). This idea can be used to automatically detect changes to the macros. It could be part of your source code but could be external as well.

It's a little extra work if and when the macros have been changed but maybe they are stable so it doesn't happen very often. And you do get notice also when the macros have been changed but still compile cleanly which can be a big advantage if there are strange errors. Personally I would prefer this solution rather than having to degrade my own design due to some third party library.

[Priya456]

What you can do is define a macro in a header file and include that header in both C and C++ source files where you want to use that macro. Such a header would need to contain only code that comes from the common subset of C and C++ so it will be acceptable in both languages.