Bug report

Bug report

[Karl JH Millar]

I get a compiler error compiling the following

template<class I, class J>
class Map {
 public:
  typedef I* iterator;
};

template<class T>
void foo(T a) {
  Map<int, T>::iterator i;
}

void bar() {
  int x;
  foo(x);
}

The result of trying to compile is

gcc -c -v template.cc -pedantic
Reading specs from /usr/local/lib/gcc-lib/i686-linux-gnu/egcs-2.91.57/specs
gcc version egcs-2.91.57 19980901 (egcs-1.1 release)
 /usr/local/lib/gcc-lib/i686-linux-gnu/egcs-2.91.57/cpp -lang-c++ -v -undef -D__GNUC__=2 -D__GNUG__=2 -D__cplusplus -D__GNUC_MINOR__=91 -D__ELF__ -Dunix -Dlinux -D__ELF__ -D__unix__ -D__linux__ -D__unix -D__linux -Asystem(posix) -D__EXCEPTIONS -pedantic -Asystem(unix) -Acpu(i386) -Amachine(i386) -Di386 -D__i386 -D__i386__ -Di686 -Dpentiumpro -D__i686 -D__i686__ -D__pentiumpro -D__pentiumpro__ template.cc /tmp/ccP2gdme.ii
GNU CPP version egcs-2.91.57 19980901 (egcs-1.1 release) (i386 Linux/ELF)
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include/g++
 /usr/local/include
 /usr/local/i686-linux-gnu/include
 /usr/local/lib/gcc-lib/i686-linux-gnu/egcs-2.91.57/include
 /usr/include
End of search list.
 /usr/local/lib/gcc-lib/i686-linux-gnu/egcs-2.91.57/cc1plus /tmp/ccP2gdme.ii -quiet -dumpbase template.cc -pedantic -version -o /tmp/cc3GC1hi.s
GNU C++ version egcs-2.91.57 19980901 (egcs-1.1 release) (i686-linux-gnu) compiled by GNU C version egcs-2.91.57 19980901 (egcs-1.1 release).
template.cc: In function `void foo(T)':
template.cc:9: parse error before `;'

I don't get the error compiling without -pedantic.
My system is a Linux/GNU system, (version 2.1.125 of the kernel) running on a
Cyrix PR 200MX processor. The egcs version is egcs-1.1a (egcs-2.91.57 19980901)
I don't know off hand the options I passed to configure, but it was nothing
unusual.

Karl Millar.

Re: Bug report

[Alexandre Oliva]

On Dec 10, 1998, Karl JH Millar <kmillar@MIT.EDU> wrote:

> template<class T>
> void foo(T a) {
>   Map<int, T>::iterator i;
  ^ you need the `typename' keyword here

-- 
Alexandre Oliva  http://www.dcc.unicamp.br/~oliva  aoliva@{acm.org}
oliva@{dcc.unicamp.br,gnu.org,egcs.cygnus.com,samba.org}
Universidade Estadual de Campinas, SP, Brasil

Explict typename

[Gerald Pfeifer]

On Thu, 10 Dec 1998, Karl JH Millar wrote:
> template<class T>
> void foo(T a) {
>   Map<int, T>::iterator i;
> }
> 
> gcc -c -v template.cc -pedantic
> 
> I don't get the error compiling without -pedantic.

Your code is in error but this bug is only detected with -pedantic.
Correctly you should have written: typename Map<int, T>::iterator i.


To our C++ experts: This is reported over and over again, so I strongly
suggest that

 o the implicit typename extension issues a warning whenever it comes
   into play.

 o a better error message is issued instead of "parse error" when 
   -pedantic is used.

Gerald
-- 
Gerald Pfeifer (Jerry)      Vienna University of Technology
pfeifer@dbai.tuwien.ac.at   http://www.dbai.tuwien.ac.at/~pfeifer/

Re: Explict typename

[Gabriel Dos Reis]

>>>>> Gerald Pfeifer <pfeifer@dbai.tuwien.ac.at> wrote:

> On Thu, 10 Dec 1998, Karl JH Millar wrote:
>> template<class T>
>> void foo(T a) {
>> Map<int, T>::iterator i;
>> }
>> 
>> gcc -c -v template.cc -pedantic
>> 
>> I don't get the error compiling without -pedantic.

> Your code is in error but this bug is only detected with -pedantic.
> Correctly you should have written: typename Map<int, T>::iterator i.


> To our C++ experts: This is reported over and over again, so I strongly
> suggest that

>  o the implicit typename extension issues a warning whenever it comes
>    into play.

I recall having made suggestions along these lines a long time ago but...

>  o a better error message is issued instead of "parse error" when 
>    -pedantic is used.


I agree.

-- Gaby