https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105499
--- Comment #2 from Vincent Lefèvre <vincent-gcc at vinc17 dot net> --- (In reply to Eric Gallager from comment #1) > This is probably another one of those issues with how the preprocessor works > in C++ mode in general; see for example bug 71003 and bug 87274 Note, however, that bug 71003 and bug 87274 are about parsing (complaints about an escape sequence and numeric literals), while in this PR, the error occurs at the semantic level (type issues). Does the preprocessor know about types?