[Bug c++/17459] New: Spurious message when forgetting parentheses on call of member

[Bug c++/17459] New: Spurious message when forgetting parentheses on call of member

[bangerth at dealii dot org]

(This is a spin-off from PR 17456) 
 
Take this code: 
----------------- 
struct S { 
  void foo(); 
  void bar() { foo; } 
}; 
----------------- 
Sure, the code looks odd: someone probably wanted to write foo() but 
forgot the parentheses. But I would think it is valid: we take a reference 
to the function S::foo and discard the result of this statement. But 
we get an error from gcc instead: 
 
g/x> /home/bangerth/bin/gcc-3.5-pre/bin/c++ -c x.cc 
x.cc: In member function `void S::bar()': 
x.cc:3: error: statement cannot resolve address of overloaded function 
 
That strikes me as completely odd and wrong: first, I think there shouldn't 
be an error in the first place; second, we certainly have no overloads 
here, so the message's intent is completely puzzling to me. Note that  
gcc2.95 printed this instead: 
 
g/x> /home/bangerth/bin/gcc-2.*/bin/c++ -c x.cc 
x.cc: In method `void S::bar()': 
x.cc:3: invalid use of member (did you forget the `&' ?) 
 
icc accepts the code without any warning or error. 
 
 
No, for comparison, think of the case where the two functions are 
non-members: 
------------------ 
void foo(); 
void bar() { foo; } 
------------------ 
Now we get 
 
g/x> /home/bangerth/bin/gcc-3.5-pre/bin/c++ -c x.cc 
x.cc: In function `void bar()': 
x.cc:2: warning: statement is a reference, not call, to function `foo' 
 
That makes more sense, and should have been what we get for the 
member case as well. 
 
W.

-- 
           Summary: Spurious message when forgetting parentheses on call of
                    member
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: bangerth at dealii dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17459

[Bug c++/17459] Spurious message when forgetting parentheses on call of member

[giovannibajo at libero dot it]

------- Additional Comments From giovannibajo at libero dot it  2004-09-13 17:33 -------
Notice that you need "&S::foo" to take the address of a member function. The 
syntax "foo(blah)" is the function call syntax, and it is available only for 
function calls.

I am not sure why EDG accepts it. Anyway, our diagnostic is suboptimal.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17459

[Bug c++/17459] Spurious message when forgetting parentheses on call of member

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-09-13 18:32 -------
Uhm, yes... I tend to take icc's acceptance as standards conformance  
sometimes :-( 
 
W. 

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-09-13 18:32:41
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17459