[Bug c++/49554] New: [4.7 Regression] [C++0x] lambda capture causes "cannot call member function ... without object"

[Bug c++/49554] New: [4.7 Regression] [C++0x] lambda capture causes "cannot call member function ... without object"

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49554

           Summary: [4.7 Regression] [C++0x] lambda capture causes "cannot
                    call member function ... without object"
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Keywords: rejects-valid
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: redi@gcc.gnu.org
                CC: jason@gcc.gnu.org


template<typename T>
  struct base
  {
    struct iterator { };

    iterator begin();
  };

template<typename T>
class flist : public base<T>
{
  typedef base<T> Base;

  typedef typename Base::iterator Base_iterator;
public:

  void
  resize()
  {
    Base_iterator b = Base::begin();

    [b](int i) { return i; };
  }
};

void test01()
{
  flist<int> fl;
  fl.resize();
}


objexpr.ii: In lambda function:
objexpr.ii:22:6:   required from ‘struct flist<T>::resize() [with T =
int]::<lambda(int)>’
objexpr.ii:22:5:   required from ‘void flist<T>::resize() [with T = int]’
objexpr.ii:29:13:   required from here
objexpr.ii:20:19: error: cannot call member function ‘base<T>::iterator
base<T>::begin() [with T = int]’ without object

If 'b' is not captured there's no error

This breaks <debug/forward_list> in libstdc++

[Bug c++/49554] [4.7 Regression] [C++0x] lambda capture causes "cannot call member function ... without object"

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49554

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-06-27 23:26:44 UTC ---
also, if 'b' is initialized like this it works:
    Base_iterator b = this->begin();

[Bug c++/49554] [4.7 Regression] [C++0x] lambda capture causes "cannot call member function ... without object"

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49554

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-06-27 23:44:05 UTC ---
No error for this version:

    Base_iterator b;
    b = Base::begin();

    [b](int i) { return i; };

[Bug c++/49554] [4.7 Regression] [C++0x] lambda capture causes "cannot call member function ... without object"

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49554

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2011.06.29 15:56:40
         AssignedTo|unassigned at gcc dot       |jason at gcc dot gnu.org
                   |gnu.org                     |
     Ever Confirmed|0                           |1

[Bug c++/49554] [4.7 Regression] [C++0x] lambda capture causes "cannot call member function ... without object"

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49554

--- Comment #3 from Jason Merrill <jason at gcc dot gnu.org> 2011-06-29 17:15:11 UTC ---
Author: jason
Date: Wed Jun 29 17:15:06 2011
New Revision: 175657

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=175657
Log:
    PR c++/49554
    * semantics.c (lambda_proxy_type): New.
    (build_capture_proxy): Use it.
    * cp-tree.h (DECLTYPE_FOR_LAMBDA_PROXY): New.
    * pt.c (tsubst) [DECLTYPE_TYPE]: Use them.

Added:
    trunk/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-template3.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/cp-tree.h
    trunk/gcc/cp/pt.c
    trunk/gcc/cp/semantics.c
    trunk/gcc/testsuite/ChangeLog

[Bug c++/49554] [4.7 Regression] [C++0x] lambda capture causes "cannot call member function ... without object"

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49554

Jason Merrill <jason at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.7.0

--- Comment #4 from Jason Merrill <jason at gcc dot gnu.org> 2011-06-29 17:26:50 UTC ---
Fixed.