How to make msvc preprocessor understand operator "and" and "or" along with &quo-CodePudding

I have code that has code like that

#if defined(A) and defined(b)
...
#endif

It fails with a lot of syntax errors which denotes that parsing failed
If I replace and with && it compiles. I don't want to make changes in thirdparty library, is there a way to make it recognize those operators?

CodePudding user response：

You can just

#include <iso646.h>

That header defines alternative tokens for the operators. But it's really not a good way. Just use the normal C operators

Demo on Godbolt

CodePudding user response：

Since in C , and and or are built-it alternative operator representations, the C version of <iso646.h> (and <ciso646>, which was removed in C 20) header file does not define anything. However, Microsoft's extensions to C conflict with those.

You can require strict language conformance by using the /permissive- switch. (Note that setting the C language standard level to C 20 using the /std:c 20 switch will automatically enable strict conformance as well).

Another way is to use the /Za switch to disable Microsoft's extensions to C language. (However, Microsoft does not recommend using /Za when code is compiled as C .)