On 6 September 2017 at 16:59, A.J. Bonnema wrote: > On 09/06/2017 03:02 PM, Jonathan Wakely wrote: >> >> >>>> That manual page specifically talks about GNU C, not C++, are you >>>> using C or C++? >>> >>> >>> I am using C. >> >> Then it should work OK, and indeed it does work OK for me using Fedora >> 26 on x86_64. > > > This completely breaks my wooden shoe! (Dutchism). > > Indeed, when I created a small program, it compiles. Doesn't run as I > expected (printf shows a different value), but it compiles and runs. > > So I went back to my project and discovered that -std=c11 is the issue: is > that even possible? Why would c11 be a problem if the _Decimal64 type is > part of C99? Or maybe I misunderstand the documents and it might be part of > the standard in the future? It's not part of any current or previous C standard, it's a TR, which is a separate document, see https://www.iso.org/deliverables-all.html The problem is that -std=c11 disables non-standard extensions. The default for gcc-7 is -std=gnu11 which includes extensions. See https://gcc.gnu.org/onlinedocs/gcc/C-Dialect-Options.html > Anyways, thank you for your time. Hopefully there is a way to combine C11 > and _Decimal. Use the -std=gnuNN options, not -std=cNN options.
