MSVC compile errors with /Zc:__cplusplus

[GIGte]

I'm using Visual Studio 2019. When I add option /Zc:__cplusplus (fixes __cplusplus macro value) it refuses to compile. I get strange errors like
yas\include\yas\types\std\pair.hpp(63,1): error C2975: '_Val': invalid template argument for 'std::integral_constant', expected compile-time constant expression

I did a quick test with file examples/one_memfn/main.cpp

This compiles:
cl main.cpp /I"../../include" /EHsc /std:c++17 /permissive-

And this does not:
cl main.cpp /I"../../include" /EHsc /std:c++17 /permissive- /Zc:__cplusplus

This probably has something to do with fnv1a function in include\yas\detail\tools\fnv1a.hpp . If you switch to the code for __cplusplus < 201402L yas compiles just fine.

[niXman]

please provide the link to the docs for /Zc:__cplusplus because I can't google it

[GIGte]

Here:
https://docs.microsoft.com/en-us/cpp/build/reference/zc-cplusplus?view=vs-2019

It simply changes the macro.

[niXman]

provide please the preprocessed code of examples/one_memfn/main.cpp source with enabled /Zc:__cplusplus

[GIGte]

Full sample one_memfn.zip

I changed YAS_THROW_EXCEPTION to __YAS_THROW_EXCEPTION because it doesn't work otherwise :)

[niXman]

hmm... there is no preprocessed code in the archive...

[niXman]

I changed YAS_THROW_EXCEPTION to __YAS_THROW_EXCEPTION because it doesn't work otherwise :)

did this solve your problem?

[GIGte]

Ah, I just didn't understand. This preprocessed code main.zip ?

did this solve your problem?

No, it didn't. This seems like a bug in the examples. The macro without the underscores cannot be found.

[niXman]

This preprocessed code main.zip ?

yes.

I think was fixed in master, please check and let me know the result.

[GIGte]

Still errors. Now
error C2664: 'uint32_t yas::detail::fnv1a(std::nullptr_t)': cannot convert argument 1 from 'char [1024]' to 'std::nullptr_t'

The function fnv1a(const CharT ...) gets skipped. I thought about #if __cplusplus >= 201402L && !defined(_MSC_VER). This does not look like the best solution but after I put this line it worked.

[niXman]

my bad, sorry.
fixed in master.
check now please.

[GIGte]

It works.

[niXman]

great, please close.