Bug 82684 - std::complex template specializations require C99 Complex
Summary: std::complex template specializations require C99 Complex
Status: RESOLVED INVALID
Alias: None
Product: gcc
Classification: Unclassified
Component: libstdc++ (show other bugs)
Version: 5.4.0
: P3 normal
Target Milestone: ---
Assignee: Not yet assigned to anyone
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2017-10-23 18:31 UTC by Christopher J. Hanks
Modified: 2017-10-25 01:17 UTC (History)
1 user (show)

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Known to fail:
Last reconfirmed: 2017-10-24 00:00:00

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Description Christopher J. Hanks 2017-10-23 18:31:59 UTC 
Tested on Ubuntu 16.04 using GLIBCXX_3.4.  The template specializations for std::complex<double | float | long double> require the presence of the C99 complex type even though the primary class template is designed to work without it.

Putting the specializations and forward declarations in an `#if _GLIBCXX_USE_C99_COMPLEX` block appears to allow code to compile as expected.


$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
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 5.4.0-6ubuntu1~16.04.4' --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 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.4)
Comment 1 Jonathan Wakely 2017-10-24 01:18:53 UTC 
(In reply to Christopher J. Hanks from comment #0)
> Tested on Ubuntu 16.04 using GLIBCXX_3.4.  The template specializations for
> std::complex<double | float | long double> require the presence of the C99
> complex type even though the primary class template is designed to work
> without it.

This is by design. What is the bug you're reporting?

> Putting the specializations and forward declarations in an `#if
> _GLIBCXX_USE_C99_COMPLEX` block appears to allow code to compile as expected.

What code? What doesn't compile without those changes?
Comment 2 Christopher J. Hanks 2017-10-25 00:41:54 UTC 
> > Putting the specializations and forward declarations in an `#if
> > _GLIBCXX_USE_C99_COMPLEX` block appears to allow code to compile as expected.
> 
> What code? What doesn't compile without those changes?

Apologies, I have conflated the C99 complex type operations with the GNU extensions.
Comment 3 Jonathan Wakely 2017-10-25 01:17:53 UTC 
Closing then.