Protect macro expansion of commonly defined macros

[SylvainCorlay]

Wrapping std::min and std::max in parentheses prevents the expansion of windows' min and max macros. I agree these should have never existed in the first place, but that would allow windows users to make use of nlohmann_json without setting NOMINMAX.

Similarly, Python.h defines snprintf as a macro. Wrapping calls in parentheses would also prevent the expansion of this macro.

So the fix would be to replace instances of std::snprintf with (std::snprintf), similarly to what is done with std::max and std::min.

[nlohmann]

I am not sure what this issue proposes - adding parentheses around min and max? Then point me to a place where the parentheses are missing.

[SylvainCorlay]

Sorry if I was not clear. I was suggesting to do the same with snprintf as for min and max, that is to wrap it in parentheses. snprintf is defined as a macro by Python.h (as equal to _snprintf).

I met the issue for std::snprintf, which is used in serializer.hpp and binary_reader.hpp.

[nlohmann]

Thanks for clarifying! I shall have a look.

[nlohmann]

@SylvainCorlay Could you please check whether https://github.com/nlohmann/json/tree/feature/snprintf fixes the issue?

[SylvainCorlay]

@nlohmann thanks! I could check and it works perfectly!

[nlohmann]

Thanks for the feedback!

[SylvainCorlay]

Thanks @nlohmann. And thanks for the great work on this library!