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From: "schaub.johannes at googlemail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/49205] New: Default constructor with pack expansion parameter not detected
Date: Sat, 28 May 2011 00:48:00 -0000	[thread overview]
Message-ID: <bug-49205-4@http.gcc.gnu.org/bugzilla/> (raw)

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49205

           Summary: Default constructor with pack expansion parameter not
                    detected
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: schaub.johannes@googlemail.com


This is rejected as "ambiguous" by GCC:

struct A { 
  template<typename ...T> A(T...); 
  A(initializer_list<short>); 
  A(initializer_list<long>); 
}; 

A a{};

But in fact, 8.5.4p3:

"If the initializer list has no elements and T is a class type with a default
constructor, the object is value-initialized."

And 12.1p5:

"A default constructor for a class X is a constructor of class X that can be
called without an argument."

So, there is no ambiguity. The default ctor is called, and "T" is deduced to
"<>"(empty pack).


             reply	other threads:[~2011-05-28  0:41 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-28  0:48 schaub.johannes at googlemail dot com [this message]
2011-05-28  1:46 ` [Bug c++/49205] " coppro at users dot sourceforge.net
2011-05-28  1:55 ` [Bug c++/49205] [C++0x] " schaub.johannes at googlemail dot com
2011-05-28  2:06 ` scshunt at csclub dot uwaterloo.ca
2011-05-28  3:22 ` schaub.johannes at googlemail dot com
2011-06-20  1:53 ` jason at gcc dot gnu.org
2011-06-20 14:41 ` jason at gcc dot gnu.org
2011-06-20 14:46 ` jason at gcc dot gnu.org
2011-06-20 15:57 ` schaub.johannes at googlemail dot com

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