Annex D (normative) Compatibility features [depr]

D.9 C headers [depr.c.headers]

D.9.2 Header <iso646.h> synopsis [depr.iso646.h.syn]

1
#
The C++ header <iso646.h> is empty.
[ Note
:
and, and_­eq, bitand, bitor, compl, not_­eq, not, or, or_­eq, xor, and xor_­eq are keywords in this International Standard ([lex.key]).
— end note
 ]