[Bug c++/31986] New: conversion-type-id should match in both contexts

[Bug c++/31986] New: conversion-type-id should match in both contexts

[andrew dot stubbs at st dot com]

The following C++ program should not compile:

#include <stdio.h>

class C
{
public:
  typedef float T;
  operator T() {return 1;};
  operator int() {return 2;};
} c;

int
main ()
{
  typedef int T;
  printf ("%d\n", (T) c.operator T());  // invalid
  printf ("%d\n", T(c));
  printf ("%d\n", (T)c);
}

The C++ standard, clause 3.4.5, paragraph 7, says that the `T' should refer to
the same type in both `C' and `main'.

The output from this program, with GCC 4.1.1, is "1 2 2" (i.e. a `float' and
two `int's). This shows that the name `T' is significant here.


-- 
           Summary: conversion-type-id should match in both contexts
           Product: gcc
           Version: 4.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: andrew dot stubbs at st dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31986

[Bug c++/31986] conversion-type-id should match in both contexts

[andrew dot stubbs at st dot com]

------- Comment #1 from andrew dot stubbs at st dot com  2007-05-18 14:54 -------
EDG version 3.8 gives the warning:

t.cpp", line 15: warning: 
          ambiguous class member reference -- type "T" (declared at line 14)
          used in preference to type "C::T" (declared at line 6)
    printf ("%d\n", (T) c.operator T());  // invalid
                                   ^

In contrast to GCC, this gives the output "2 2 2", not "1 2 2".

And in -strict mode (full standard conformance) gives the error:
t.cpp", line 15: error: 
          ambiguous class member reference -- type "T" (declared at line 14)
          used in preference to type "C::T" (declared at line 6)
    printf ("%d\n", (T) c.operator T());  // invalid
                                   ^


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31986

[Bug c++/31986] conversion-type-id should match in both contexts

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31986

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |accepts-invalid, wrong-code
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-01-28
     Ever Confirmed|0                           |1
      Known to fail|                            |4.7.0

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-01-28 02:53:17 UTC ---
Confirmed.