https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89090
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Csaba Ráduly from comment #2) > > Are you actually seeing a problem because of this? > > Not as such. What I did was to generate the pre-processed output, replace #s > with // (so the line numbers are the raw ones for the raw preprocessed file) > and compile it as if it were a regular C++ file. ... why? Just don't do that. The # lines affect how the code is compiled and are a necessary part of the standard library implementation.