Undefined symbol EOF

[cxxman]

What is the issue you have?

I am getting compilation error like "Undefined symbol EOF" with gcc9 on Ubuntu 18.04

Please describe the steps to reproduce the issue.

Include single header file json.hpp and try to compile code that uses it.

Can you provide a small but working code example?

What is the expected behavior?

I can see EOF still used in the one place in the single header. Did not check multiple headers.
After replacing with std::char_traits<char>::eof() it has started to work.
Please incorporate this small change.

And what is the actual behavior instead?

Which compiler and operating system are you using?

• Compiler: ___
• Operating system: ___

Which version of the library did you use?

• latest release version 3.9.1
• other release - please state the version: ___
• the develop branch

If you experience a compilation error: can you compile and run the unit tests?

• yes
• no - please copy/paste the error message below

[nlohmann]

I can't reproduce the issue - we use several compilers include GCC9 on Ubuntu in our CI. Indeed there is one occurrence of EOF, but we also include the required header <cstdio>. That said - I have no idea why this is a compilation error on your side. Can you compile the unit tests?

That aside, I will create a PR that replaces this occurrence.

[cxxman]

thanks! btw, when 3.9.2 can be expected?

[nlohmann]

When it's done ;)

Seriously, I have no idea...

[cxxman]

Then why not release it now? It is better to release less things but a bit more often, then release a lot but never...

[nlohmann]

Because it’s not ready yet. This is a side project - there are no deadlines here.

[apirogov]

I have this issue now with the latest version, there are two places where the EOF macro is used.

[nlohmann]

@apirogov Right, I thought it was fixed, but it seems #4179 re-introduced the issue. Which compiler do you use that does not support EOF?

[apirogov]

Well, I'm compiling with GCC, but we're using clang-tidy (LLVM 18) to check the code as part of the workflow, and it complains about the "undefined symbol". I guess it's not about supporting the symbol, but that clang(-tidy) is more pedantic (which is good, actually). I patched the release version of json.hpp (replacing EOF with std::char_traits<char>::eof(), as suggested above), and the problem went away for us.