[Bug c++/72868] Constexpr expressions mistreat case ranges

[amarquez at sigovs dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=72868

--- Comment #4 from Alex Marquez <amarquez at sigovs dot com> ---
(In reply to Daniel Krügler from comment #3)
> The quoted essentials also require you to provide the full command line (A
> range in a switch case is not Standard C++), please read about what's needed
> in the quoted document.

Cmdline:
g++ -std=gnu++1y test.cpp

Output:
test.cpp:12:1: error: static assertion failed: Oops!
 static_assert(is_single_decimal_digit(3), "Oops!");

System GCC:
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/5/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 5.2.1-22ubuntu2'
--with-bugurl=file:///usr/share/doc/gcc-5/README.Bugs
--enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-5 --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-vtable-verify --enable-libmpx --enable-plugin --with-system-zlib
--disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo
--with-java-home=/usr/lib/jvm/java-1.5.0-gcj-5-amd64/jre --enable-java-home
--with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-5-amd64
--with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-5-amd64
--with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar
--enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686
--with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib
--with-tune=generic --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 5.2.1 20151010 (Ubuntu 5.2.1-22ubuntu2)

Alternate GCC (also fails):
COLLECT_GCC=avr-g++
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/avr/6.1.1/lto-wrapper
Target: avr
Configured with: ../gcc-6-20160714/configure --prefix=/usr/local/ --target=avr
--enable-languages=c,c++ --disable-nls --disable-libssp --with-avrlibc
--enable-target-optspace --disable-threads --program-prefix=avr- --enable-lto
--with-multilib-list=avr5 --disable-tls --disable-libstdcxx
Thread model: single
gcc version 6.1.1 20160714 (GCC)