Hi,
I tried to compile quite simple code: a template and operator<<(ostreami&) for
it
(as a template function). The template is in a namespace, but operator<< I'd
like to have in the 'std' namespace.
Unfortunately, the compiler rejected the code, however other compilers
(i.e. in other versions) compiled the code without any complainits.
I'm quite sure that the code is correct, buti, to be honest, I didn't check
what c++ iso standard is saying about it.
I tested the following code on my on version 3.4.3-20050101 and then build and
tested on the 3.4.4-20050506 snapshot. The issue occured in both versions.
On the other hand, I compiled successfully the same code on g++ 3.3.5-20050130
that is installed on other (old&slow) box (gentoo, i586, for details see
below).
Additionally, I tested the same code on 2.95.x on Solaris (SunOS 5.9? - but I
don't
remember right now) - it was also compiled.
I didn't check gcc-4.x.
Summary:
The code (problem.cc):
#include<iostream>
using namespace std;
namespace a {
template<typename T> class A;
}
template<typename T>
std::ostream & std::operator<< (std::ostream &, a::A<T> const &);
namespace a
{
template<typename T> class A
{
T v;
public:
A(T _v) : v(_v) {};
friend std::ostream & std::operator<< <>(std::ostream &, A<T> const &);
};
}
template<typename T>
std::ostream & std::operator<<(std::ostream & o, a::A<T> const & aa)
{
return o << aa.v ;
}
int main()
{
a::A<float> o(16.0);
cerr << o << endl;
}
Command: g++ problem.cc
Output:
problem.cc: In instantiation of `a::A<float>':
problem.cc:32: instantiated from here
problem.cc:19: error: template-id `operator<< <>' for `std::basic_ostream<char,
std::char_traits<char> >& std::operator<<(std::basic_ostream<char,
std::char_traits<char> >&, const a::A<float>&)' does not match any template
declaration
problem.cc: In function `std::ostream& std::operator<<(std::ostream&, const
a::A<T>&) [with T = float]':
problem.cc:34: instantiated from here
problem.cc:16: error: `float a::A<float>::v' is private
problem.cc:27: error: within this context
Compilation failed on 3.4.3-20050101 and 3.4.4-20050506 on my box:
Release: 3.4.4 20050506 (prerelease)
Environment:
System: Linux baki 2.6.12-rc1baki #5 Sat Mar 26 09:01:44 UTC 2005 i686 AMD
Athlon(tm) XP 2000+ AuthenticAMD GNU/Linux
Architecture: i686
host: i686-pc-linux-gnu
build: i686-pc-linux-gnu
target: i686-pc-linux-gnu
configured with: :
(reconfigured) ./configure --prefix=/home/marciso/gcc-tmp-installatio
--enable-languages=c++
Release:3.4.3-20050110 (Gentoo Linux 3.4.3.20050110-r2, ssp-3.4.3.20050110-0,
pie-8.7.7)
Environment:
System: Linux baki 2.6.12-rc1baki #5 Sat Mar 26 09:01:44 UTC 2005 i686 AMD
Athlon(tm) XP 2000+ AuthenticAMD GNU/Linux
Architecture: i686
host: i686-pc-linux-gnu
build: i686-pc-linux-gnu
target: i686-pc-linux-gnu
configured with: /var/tmp/portage/gcc-3.4.3.20050110-r2/work/gcc-3.4.3/configure
--enable-version-specific-runtime-libs --prefix=/usr
--bindir=/usr/i686-pc-linux-gnu/gcc-bin/3.4.3-20050110
--includedir=/usr/lib/gcc/i686-pc-linux-gnu/3.4.3-20050110/include
--datadir=/usr/share/gcc-data/i686-pc-linux-gnu/3.4.3-20050110
--mandir=/usr/share/gcc-data/i686-pc-linux-gnu/3.4.3-20050110/man
--infodir=/usr/share/gcc-data/i686-pc-linux-gnu/3.4.3-20050110/info
--with-gxx-include-dir=/usr/lib/gcc/i686-pc-linux-gnu/3.4.3-20050110/include/g++-v3
--host=i686-pc-linux-gnu --disable-altivec --enable-nls
--without-included-gettext --with-system-zlib --disable-checking
--disable-werror --disable-libunwind-exceptions --disable-multilib
--enable-java-awt=gtk --enable-languages=c,c++,objc,java,f77 --enable-shared
--enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu
Compilation passed on 3.3.5-20050130:
Release: 3.3.5-20050130 (Gentoo Linux 3.3.5.20050130-r1,
ssp-3.3.5.20050130-1, pie-8.7.7.1)
Environment:
System: Linux gateway 2.6.10-hardened-r3bramka #2 Sun Feb 20 12:58:22 CET 2005
i586 GNU/Linux
Architecture: i586
host: i586-pc-linux-gnu
build: i586-pc-linux-gnu
target: i586-pc-linux-gnu
configured with:
/var/tmp/portage/gcc-3.3.5.20050130-r1/work/gcc-3.3.5/configure
--enable-version-specific-runtime-libs --prefix=/usr
--bindir=/usr/i586-pc-linux-gnu/gcc-bin/3.3.5-20050130
--includedir=/usr/lib/gcc-lib/i586-pc-linux-gnu/3.3.5-20050130/include
--datadir=/usr/share/gcc-data/i586-pc-linux-gnu/3.3.5-20050130
--mandir=/usr/share/gcc-data/i586-pc-linux-gnu/3.3.5-20050130/man
--infodir=/usr/share/gcc-data/i586-pc-linux-gnu/3.3.5-20050130/info
--with-gxx-include-dir=/usr/lib/gcc-lib/i586-pc-linux-gnu/3.3.5-20050130/include/g++-v3
--host=i586-pc-linux-gnu --disable-altivec --enable-nls
--without-included-gettext --with-system-zlib --disable-checking
--disable-werror --disable-libunwind-exceptions --disable-multilib
--disable-libgcj --enable-languages=c,c++,f77 --enable-shared
--enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu
Cheers
Marcin.
--
Summary: problem with tempalte and tempalte function compilation
in a namespace
Product: gcc
Version: 3.3.4
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: marciso at box43 dot pl
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: i686-pc-linux-gnu
GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21515
