Unexpected failure: use of undeclared identifier 'not'


On our code we are using clang-cl 13 (want to test 16 very soon). On 1 specific cpp file I’m getting the following error:

In file included from ...\omtls_crc_test.cpp:3:
In file included from .\.../omtls_crc.h:16:
...\boost/crc.hpp(678,68): error: use of undeclared identifier 'not'
        new_dividend_bits = reflect_optionally( new_dividend_bits, not reflect,

All other cpp files that include the same header don’t have this problem. Using the not operator in the cpp works as expected.
I’ve tried to reproduce this using the /EP option, though than the problem no longer appears. Right now we have a workaround using #define not !.

I’ve tried to find some options to append to the compilation command to find out some more info, though, I was not able to find any.

Do you have any ideas on how to get some more info out of the compiler to understand why this is happening? Do you know where in the clang code this error would be printed?