Re: c++/8806: gcc accepts bad argument for template template parameter

Re: c++/8806: gcc accepts bad argument for template template parameter

[reichelt]

Synopsis: gcc accepts bad argument for template template parameter

State-Changed-From-To: open->analyzed
State-Changed-By: reichelt
State-Changed-When: Wed Dec  4 06:31:52 2002
State-Changed-Why:
    Confirmed.
    gcc wrongly accepts this at least since gcc 2.95.x.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=8806

Re: c++/8806: gcc accepts bad argument for template template parameter

[lerdsuwa]

Synopsis: gcc accepts bad argument for template template parameter

Responsible-Changed-From-To: unassigned->lerdsuwa
Responsible-Changed-By: lerdsuwa
Responsible-Changed-When: Thu Dec 19 07:04:36 2002
Responsible-Changed-Why:
    I will fix this in the trunk after new parser merge.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=8806

Re: c++/8806: gcc accepts bad argument for template template parameter

[Wolfgang Bangerth]

The following reply was made to PR c++/8806; it has been noted by GNATS.

From: Wolfgang Bangerth <bangerth@ticam.utexas.edu>
To: gcc-bugs@gcc.gnu.org, <gcc-gnats@gcc.gnu.org>,
   Volker Reichelt <reichelt@igpm.rwth-aachen.de>, <catherin@ca.ibm.com>
Cc:  
Subject: Re: c++/8806: gcc accepts bad argument for template template parameter
Date: Wed, 4 Dec 2002 08:36:05 -0600 (CST)

 This is actually kind of a funny problem (an oversight in the standard?),
 and the only way I can think of to make this go the intended way would be
 to write
   foo< ::bar>
 or maybe
   foo<template bar>
 
 The first is accepted by newer compilers, the latter is
 not.
 
 Regards
   Wolfgang
 
 -------------------------------------------------------------------------
 Wolfgang Bangerth              email:           bangerth@ticam.utexas.edu
                                www: http://www.ticam.utexas.edu/~bangerth
 
 

c++/8806: gcc accepts bad argument for template template parameter

[catherin]

>Number:         8806
>Category:       c++
>Synopsis:       gcc accepts bad argument for template template parameter
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Dec 04 06:16:29 PST 2002
>Closed-Date:
>Last-Modified:
>Originator:     Catherine Morton
>Release:        unknown-1.0
>Organization:
>Environment:
GNU C++ version 3.2 (powerpc-suse-linux)
>Description:
// --------------------------------------------
template < template <class A> class B> class foo{};

template < class C > class bar
{
   foo<bar> x;
};

bar<int> test;
// ---------------------------------------------

This is invalid according to section 14.6.1 paragraph 2
"Within the scope of a class template specialization or partial specialization, when the
 name of the template is neither qualified nor followed by <, it is equivalent to the name of the 
 template followed by the template-arguments enclosed in <>."

So, in the specialization bar<int> the reference bar is actually bar<int> which does not
match the template template parameter in class foo...
>How-To-Repeat:
// --------------------------------------------
template < template <class A> class B> class foo{};

template < class C > class bar
{
   foo<bar> x;
};

bar<int> test;
// ---------------------------------------------

g++ small.cpp
> > no errors

should issue an error message such as:
"small.cpp", line 5.8: 1540-0716 (S) The template argument "bar<int>" does not match the template parameter "template class B".
"small.cpp", line 8.10: 1540-0700 (I) The previous message was produced while processing "class bar<int>".
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: