[Bug c++/16068] New: Bad error message

[Bug c++/16068] New: Bad error message

[igodard at pacbell dot net]

In:

#include    <iostream>
class A{};

template<typename T>
void    operator<<(const A&, const T& t) {}

int main() {
    A a;
    a << std::endl;
    }

You get the message:

~/ootbc/common/test/src$ g++ foo1.cc
foo1.cc: In function `int main()':
foo1.cc:9: error: no match for 'operator<<' in 'a << std::endl'


While there is an error here, it is that there are multiple matches (endl is an overloaded function, all of which match) and is ambiguous, rather than that there are no matches. The error should should the usual unresolvable ambiguity message listing the ambiguous identifications.

This bug is related to #16058, which was (incorrectly) reported as an indentification error as a result of a message like this.

Ivan

-- 
           Summary: Bad error message
           Product: gcc
           Version: 3.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: igodard at pacbell dot net
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16068

[Bug c++/16068] Bad error message

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-06-19 01:13 -------
ICC 6.0 gives:
pr16070.cc
pr16070.cc(9): error: no operator "<<" matches these operands
            operand types are: A << <unknown-type>
      a << f;
        ^

compilation aborted for pr16070.cc (code 2)

Reduced:
template <class T> void f(T);
class A{};
template<typename T>
void    operator<<(const A&, const T& t) {}
int main() {  A a;  a << f; }

3.0.4 and 2.95.3 gives:
tin:~/src/gnu/gcctest>~/ia32_linux_gcc3_0/bin/gcc pr16070.cc
pr16070.cc: In function `int main()':
pr16070.cc:9: no match for `A& << <unknown type>' operator
tin:~/src/gnu/gcctest>~/ia32_linux_gcc2_95//bin/gcc pr16070.cc
pr16070.cc: In function `int main()':
pr16070.cc:9: no match for `A & << {unknown type}'

They are slightly better but still bad (really ICC's diagnostic is just as bad as GCC's here).

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
           Keywords|                            |diagnostic
   Last reconfirmed|0000-00-00 00:00:00         |2004-06-19 01:13:19
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16068

[Bug c++/16068] Bad error message

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-06-19 01:21 -------
*** Bug 16069 has been marked as a duplicate of this bug. ***

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16068

[Bug c++/16068] Bad error message

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-03-04 07:51 -------
*** Bug 20311 has been marked as a duplicate of this bug. ***

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16068

[Bug c++/16068] Bad error message

[pinskia at gcc dot gnu dot org]

------- Comment #4 from pinskia at gcc dot gnu dot org  2005-10-04 02:31 -------
Fixed by:
        * error.c (dump_type) <UNKNOWN_TYPE>: Print reworded message.
        * g++.dg/overload/unknown1.C: New.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16068