I wrote: > A larger issue is that it looks like ICU68 may insist on importing > <stdbool.h> in some headers. That's fine on the platforms where we > use <stdbool.h> anyway, but it's distinctly not fine elsewhere. Meh. I went to see if I could test that, and didn't get much further than this on ICU's downloads page: ICU4C Platform Support All: Compiler support for C++11 is required for building the ICU libraries. Some platforms (such as IBM AIX, IBM z and Solaris) may no longer be able to build ICU until an improved compiler is available. AFAIK, the only platforms we have where <stdbool.h> isn't used are PPC Mac, which of course was discontinued around 2008, so there's zero chance that the compiler supports C++11. Barring somebody finding evidence of a platform that can run ICU68 and is not using <stdbool.h>, it's not worth spending time on this combination. I think we should just s/TRUE/true/ and be done with it. regards, tom lane