[Bug c++/42687] New: The prevention of ADL with the help of parentheses doesn't work

[Bug c++/42687] New: The prevention of ADL with the help of parentheses doesn't work

[max at e-soft dot ru]

g++ doesn't accept correct code:

namespace N
{
    struct S { };
    void f(const S &) { }
}

void f(const N::S &) { }

int main()
{
    N::S v;
    (f)(v); // no ambiguity: ADL is prevented with (), only ::f is considered
}

--------------------------------------
References:

    1) http://www.josuttis.com/tmplbook/ - "9.2.1 Argument-Dependent Lookup",
page 123.

    2) http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n3000.pdf -
"3.4.2 Argument-dependent name lookup", example on page 46.


-- 
           Summary: The prevention of ADL with the help of parentheses
                    doesn't work
           Product: gcc
           Version: 4.4.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: max at e-soft dot ru


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42687

[Bug c++/42687] The prevention of ADL with the help of parentheses doesn't work

[jwakely dot gcc at gmail dot com]

------- Comment #1 from jwakely dot gcc at gmail dot com  2010-01-11 18:37 -------
This was changed by
http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#705 and didn't
appear in the working draft until November.
It's hardly surprising that a compiler released in October doesn't support it


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42687

[Bug c++/42687] The prevention of ADL with the help of parentheses doesn't work

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42687

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |rejects-valid
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011.03.29 13:46:50
     Ever Confirmed|0                           |1

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-03-29 13:46:50 UTC ---
(In reply to comment #2)
> This is still not fixed in trunk.

Yup, that's why the bug report is still open.
It can be confimed though.

[Bug c++/42687] The prevention of ADL with the help of parentheses doesn't work

[f.sowade-gcc at r9e dot de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42687

Florian Sowade <f.sowade-gcc at r9e dot de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |f.sowade-gcc at r9e dot de

--- Comment #2 from Florian Sowade <f.sowade-gcc at r9e dot de> 2011-03-29 13:27:51 UTC ---
The change in http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#705
only changed the wording to make this behavior clearer.
But the behavior itself is, like clearly argumented there, implied by the old
version of 3.4.2.

This is still not fixed in trunk. Neither in c++0x mode with the explicit
wording in the standard, nor in c++03 mode with the more subtle wording in the
standard.