On Wed, 19 Jun 2019 at 20:00, Jonathan Wakely <jwakely.gcc@xxxxxxxxx> wrote: > > On Wed, 19 Jun 2019, 19:07 ba58smith, <ba58smith@xxxxxxxxx> wrote: > > > > @Marc Glisse-6, > > > > Thanks for that, but can you provide a little more info, please? I'm to > > create a text file called empty.cc, and its contents should be: > > > No, create an EMPTY file. With no contents. Then run the commands Marc > showed you, and it will answer your question. > > > > > > Create an empty file empty.cc, then > > > > $ g++ -E -dM e.cc > 1 > > $ g++ -E -dM e.cc -fno-rtti > 2 > > $ diff 1 2 > > 108d107 > > < #define __GXX_RTTI 1 > > 202d200 > > < #define __cpp_rtti 199711 > > > > Is that right? And then what do I do with it? Sorry - this is way > > lower-level coding than I'm used to. Thanks. > > This is not low-level coding, it's running two g++ commands (with rtti > enabled and without) and comparing the output. And the point is to demonstrate that there are two macros defined when RTTI is enabled, __GXX_RTTI (as Marc said, you got the number of underscores wrong), and __cpp_rtti. I have no idea where you got _CPP_RTTI, maybe that's meant to be __cpp_rtti and you got the number of underscores and capitlization wrong.
