> 53 #if defined __cplusplus > 54 # define YY_CPLUSPLUS __cplusplus > 55 #else > 56 # define YY_CPLUSPLUS 199711L > 57 #endif > > Please check why your compiler does not define __cplusplus. Compliant > compilers > must define it properly so that we can know what version of C++17 we're in. > See https://en.cppreference.com/w/cpp/preprocessor/replace#Predefined_macros.
It is defined. Just not what we think it should be. It is 199711L I've never had to check the value of __cplusplus, just if it existed or not. After some digging, I found this: "You need to compile with the /Zc:__cplusplus switch to see the updated value of the __cplusplus macro. We tried updating the macro by default and discovered that a lot of code doesn’t compile correctly when we change the value of __cplusplus" Source: https://devblogs.microsoft.com/cppblog/msvc-now-correctly-reports-__cplusplus/ Without this /Zc switch, the Microsoft compiler seems to default __cplusplus to 199711L This switch is not on by default. I honestly can't find the words to express how I feel about this. Sorry to bother you, Thanks for your help
