[Bug c++/44158] [C++0x] wrong overload resolution for copy-initialization from an rvalue

[jason at gcc dot gnu dot org]

--- Comment #8 from jason at gcc dot gnu dot org  2010-05-19 15:49 ---
Subject: Bug 44158

Author: jason
Date: Wed May 19 15:49:01 2010
New Revision: 159577

URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=159577
Log:
PR c++/44158
* call.c (build_over_call): Don't do bitwise copy for move ctor.

Modified:
branches/gcc-4_5-branch/gcc/cp/ChangeLog
branches/gcc-4_5-branch/gcc/cp/call.c
branches/gcc-4_5-branch/gcc/testsuite/ChangeLog
branches/gcc-4_5-branch/gcc/testsuite/g++.dg/cpp0x/rv-trivial-bug.C


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44158

[Bug c++/44158] [C++0x] wrong overload resolution for copy-initialization from an rvalue

[jason at gcc dot gnu dot org]

--- Comment #9 from jason at gcc dot gnu dot org  2010-05-19 16:10 ---
Fixed for 4.5.1.


-- 

jason at gcc dot gnu dot org changed:

   What|Removed |Added

 Status|ASSIGNED|RESOLVED
 Resolution||FIXED
   Target Milestone|--- |4.5.1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44158

[Bug c++/44158] [C++0x] wrong overload resolution for copy-initialization from an rvalue

[jason at gcc dot gnu dot org]

--- Comment #7 from jason at gcc dot gnu dot org  2010-05-17 19:54 ---
Subject: Bug 44158

Author: jason
Date: Mon May 17 19:53:45 2010
New Revision: 159508

URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=159508
Log:
PR c++/44158
* call.c (build_over_call): Don't do bitwise copy for move ctor.

Modified:
trunk/gcc/cp/ChangeLog
trunk/gcc/cp/call.c
trunk/gcc/testsuite/ChangeLog
trunk/gcc/testsuite/g++.dg/cpp0x/rv-trivial-bug.C


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44158

[Bug c++/44158] [C++0x] wrong overload resolution for copy-initialization from an rvalue

[redi at gcc dot gnu dot org]

--- Comment #1 from redi at gcc dot gnu dot org  2010-05-16 17:07 ---
The rules say that for copy-initialization where the source type (X) is not
the same as the destination type (X) a temporary is created. That temporary is
copy-constructed from x, then y is move-constructed from the temporary.

To avoid the temporary use direct-initialization;

Y y( static_castX(x) );


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44158

[Bug c++/44158] [C++0x] wrong overload resolution for copy-initialization from an rvalue

[redi at gcc dot gnu dot org]

--- Comment #2 from redi at gcc dot gnu dot org  2010-05-16 17:08 ---
(In reply to comment #1)
 Y y( static_castX(x) );
  ^
Oops. I meant X not Y


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44158

[Bug c++/44158] [C++0x] wrong overload resolution for copy-initialization from an rvalue

[paolo dot carlini at oracle dot com]

--- Comment #3 from paolo dot carlini at oracle dot com  2010-05-16 18:29 
---
This is invalid then.


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paolo dot carlini at oracle dot com changed:

   What|Removed |Added

 Status|UNCONFIRMED |RESOLVED
 Resolution||INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44158

[Bug c++/44158] [C++0x] wrong overload resolution for copy-initialization from an rvalue

[redi at gcc dot gnu dot org]

--- Comment #4 from redi at gcc dot gnu dot org  2010-05-16 19:34 ---
it might be a valid enhancement request, as I think the temporary is eligible
for copy-elision (Jason?) but the compiler isn't required to elide it, so it is
wrong to assert that a temporary won't be created


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44158

[Bug c++/44158] [C++0x] wrong overload resolution for copy-initialization from an rvalue

[paolo dot carlini at oracle dot com]

--- Comment #5 from paolo dot carlini at oracle dot com  2010-05-16 21:25 
---
To be safe, let's reopen the bug. For the record, this works:

#include cassert

struct X
{
  X(int i) : i_(i) {}
  X(X x) : i_(x.i_) { x.i_ = 0; }
  int i_;

  X(const X) = delete;
};

int main()
{
  X x(42);
  X y = static_castX(x);
  assert( y.i_ == 42 );
  assert( x.i_ == 0 );
}


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paolo dot carlini at oracle dot com changed:

   What|Removed |Added

 Status|RESOLVED|UNCONFIRMED
 Resolution|INVALID |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44158

[Bug c++/44158] [C++0x] wrong overload resolution for copy-initialization from an rvalue

[jason at gcc dot gnu dot org]

--- Comment #6 from jason at gcc dot gnu dot org  2010-05-16 22:32 ---
(In reply to comment #1)
 The rules say that for copy-initialization where the source type (X) is not
 the same as the destination type (X) a temporary is created.

But the source type is X; there are no expressions of reference type.

The problem is not the overload resolution, but that build_over_call looks at
TYPE_HAS_COMPLEX_INIT_REF even though we're dealing with the move ctor, not the
copy ctor.


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jason at gcc dot gnu dot org changed:

   What|Removed |Added

 Status|UNCONFIRMED |NEW
 Ever Confirmed|0   |1
   Last reconfirmed|-00-00 00:00:00 |2010-05-16 22:32:43
   date||


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44158

[Bug c++/44158] [C++0x] wrong overload resolution for copy-initialization from an rvalue

[jason at gcc dot gnu dot org]

-- 

jason at gcc dot gnu dot org changed:

   What|Removed |Added

 AssignedTo|unassigned at gcc dot gnu   |jason at gcc dot gnu dot org
   |dot org |
 Status|NEW |ASSIGNED
   Last reconfirmed|2010-05-16 22:32:43 |2010-05-16 23:21:43
   date||


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44158