Re: template bug

["Martin v. Loewis" <martin@loewis.home.cs.tu-berlin.de>]

> g++ should be able to resolve the call to the overloaded function:

Thanks for your bug report. This is not a bug in the compiler, but in
your code. Both candidates are viable, they require the same
conversion sequences on arguments, and neither is as specialized as
the other.

If you question this line of reasoning, please discuss it in one of
the public C++ fora first, eg. comp.lang.c++.moderated, or
comp.std.c++.

Regards,
Martin
>From ovi@physics.utoronto.ca Wed Apr 19 14:16:00 2000
From: Ovidiu Toader <ovi@physics.utoronto.ca>
To: gcc-bugs@gcc.gnu.org
Subject: gcc-2_95-branch bootstrap failure
Date: Wed, 19 Apr 2000 14:16:00 -0000
Message-id: <38FE21DB.2A8CF751@physics.utoronto.ca>
X-SW-Source: 2000-04/msg00544.html
Content-length: 1791

phoenix:lang/gcc/egcs.rls> uname -a
Linux phoenix.physics.utoronto.ca 2.2.14 #5 Mon Feb 7 18:45:19 EST 2000
alpha unknown
phoenix:lang/gcc/egcs.rls> gmake CFLAGS='-O2' LIBCFLAGS='-g -O2'
LIBCXXFLAGS='-g -O2 -fno-implicit-templates' bootstrap-lean
...
...
cp stdlist tlist
if [ x"yes" = xyes ]; then \
  sed 's,\([A-Za-z_]*\.o\),pic/\1,g' tlist > tlist2 ; \
  mv tlist2 tlist ; \
else true ; fi
mv tlist piclist
/usr/local/Packages/lang/gcc/egcs.rls/objects/gcc/xgcc
-B/usr/local/Packages/lang/gcc/egcs.rls/objects/gcc/
-B/usr/local/Packages/lang/gcc/egcs.rls/install/alph
aev6-unknown-linux-gnu/bin/ -g -O2 -fvtable-thunks -D_GNU_SOURCE
-fno-implicit-templates -Wl,-soname,libstdc++-libc6.1-2.so.3 -shared -o
libstdc++-3-libc6.1-2-2.10.0.so `cat piclist` -lm
../libio/pic/strstream.o: In function `iostream::iostream(int)':
/usr/local/Packages/lang/gcc/egcs.rls/objects/alphaev6-unknown-linux-gnu/libio/../../../egcs/libio/strstream.h:83:
multiple definition of`iostream::iostream(int)'
../libio/pic/fstream.o(.text+0x0):/usr/local/Packages/lang/gcc/egcs.rls/objects/alphaev6-unknown-linux-gnu/libio/../../../egcs/libio/fstream.cc:
first defined here
../libio/pic/pfstream.o: In function `ofstream::ofstream(int)':
/usr/local/Packages/lang/gcc/egcs.rls/objects/alphaev6-unknown-linux-gnu/libio/../../../egcs/libio/pfstream.cc:74:
multiple definition of
`ofstream::ofstream(int)'../libio/pic/PlotFile.o(.text+0x0):/usr/local/Packages/lang/gcc/egcs.rls/objects/alphaev6-unknown-linux-gnu/libio/../../../egcs/libio/PlotFile.cc:
first defined here
collect2: ld returned 1 exit status
gmake[1]: *** [libstdc++-3-libc6.1-2-2.10.0.so] Error 1
gmake[1]: Leaving directory
`/usr/local/Packages/lang/gcc/egcs.rls/objects/alphaev6-unknown-linux-gnu/libstdc++'
gmake: *** [all-target-libstdc++] Error 2
>From rolly@free.fr Wed Apr 19 14:18:00 2000
From: Arnaud Rolly <rolly@free.fr>
To: gcc-bugs@gcc.gnu.org
Subject: GCC Bug ?
Date: Wed, 19 Apr 2000 14:18:00 -0000
Message-id: <00041922441000.01083@localhost.localdomain>
X-SW-Source: 2000-04/msg00545.html
Content-length: 521

I've a problem with gcc :

[root@localhost audio]# g++ -c sound.cpp
sound.cpp:20: Internal compiler error.
sound.cpp:20: Please submit a full bug report.
sound.cpp:20: See <URL: http://www.gnu.org/software/gcc/faq.html#bugreport > for instructions.
[root@localhost audio]# g++ -v
Reading specs from /usr/lib/gcc-lib/i586-mandrake-linux/2.95.2/specs
gcc version 2.95.2 19991024 (release) 

I've the Mandrake 7.0.

The 'problematic files' are attached to the mail.

Please keep me informed.

-- 
Arnaud Rolly
rolly@free.fr
>From martin@loewis.home.cs.tu-berlin.de Wed Apr 19 14:53:00 2000
From: "Martin v. Loewis" <martin@loewis.home.cs.tu-berlin.de>
To: laufreeman@hotmail.com
Cc: gcc-bugs@gcc.gnu.org
Subject: Re: Help me ,nested template!!!!!!!!!!!!!!!
Date: Wed, 19 Apr 2000 14:53:00 -0000
Message-id: <200004192147.XAA01514@loewis.home.cs.tu-berlin.de>
References: <20000414130908.87654.qmail@hotmail.com>
X-SW-Source: 2000-04/msg00546.html
Content-length: 1103

> I defined a template class Poly in poly.h
> template <class T,class S>
> class Poly{
>         .
>         .
>         .
>         .
> //and a friend function
> 
> friend Poly<T,S>  operator* <>(const T &c,const Poly<T,S> &pl) ;
> };

I guess you also have an operator* in that function. In standard C++,
you should now write

 friend Poly<T,S>  ::operator* <>(const T &c,const Poly<T,S> &pl) ;

because operator* probably refers to the other operator* in the class,
not to the global function.

> but I used g++2.905 and succeeded,what should I do?

A number of things. First, please try to get familiar with the bug
reporting instructions, as summarized in

http://www.gnu.org/software/gcc/bugs.html

Also, have a look at the section "Reporting Bugs". If you really want
to report a bug, you must include all details.

If you want to get your code working, I recommend removing the friend
declaration, and arranging the members that this operator needs to
access to be public members. Alternatively, you could also introduce a
helper friend function which is not called operator*.

Regards,
Martin