compile time errors due to changes in stl_list.h code

From:
fimarn <fimarn@gmail.com>
Newsgroups:
comp.lang.c++.moderated
Date:
Wed, 18 Jul 2007 09:59:19 CST
Message-ID:
<1184765635.738932.266130@e16g2000pri.googlegroups.com>
I am trying to get rid of compile time error that I am getting only in
RHEL5
(not in RHEL4) apparently due to the changes in the stl_list.h file.
The error that I am getting is coming from the following code that
attempts
to remove an item from the list:

class shm_objptr_list : public std::list < void*, SharedMemAlloc<void
*> >
{
.....
 bool remove(void *data) {
   iterator l_iter = find(data);

   if(l_iter == end()) return false;
   erase(l_iter); // <=== Compiler flags this line
   return true;
 }

========================
The allocator is declared as :

template<class T>
class SharedMemAlloc {

public:
   typedef size_t size_type;
   typedef ptrdiff_t difference_type;
   typedef T *pointer;
   typedef const T *const_pointer;
   typedef T& reference;
   typedef const T& const_reference;
   typedef T value_type;

   template <class _T> struct rebind {
     typedef SharedMemAlloc<_T> other;
   };

     static pointer allocate(size_type n)
   {
     return (pointer)SharedMemObj::allocate(n);
   }
   static void deallocate(void* p, size_type n)
   {
     SharedMemObj::deallocate(p, n);
   }

   void construct(pointer p, const T&val) {new (p) T(val); }
   void destroy(pointer p) {p->~T(); }

};
==============================================
The error looks like this:

/usr/lib/gcc/i386-redhat-linux/4.1.1/../../../../include/c++/4.1.1/
bits/stl_list.h:
In member function typename _Alloc::rebind<_Tp >::other
std::_List_base<_Tp,
_Alloc>::_M_get_Tp_allocator() const [with _Tp = void*, _Alloc =
SharedMemAlloc<std::_List_node<void* > >]:

/usr/lib/gcc/i386-redhat-linux/4.1.1/../../../../include/c++/4.1.1/
bits/stl_list.h:1149:
instantiated from void std::list<_Tp, _
Alloc>::_M_erase(std::_List_iterator<_Tp>) [with _Tp = void*, _Alloc =
SharedMemAlloc<std::_List_node<void*> >]

/usr/lib/gcc/i386-redhat-linux/4.1.1/../../../../include/c++/4.1.1/
bits/list.tcc:98:
instantiated from 'typename std::list<_Tp, _ Alloc>::iterator
std::list<_Tp,
_Alloc>::erase(std::_List_iterator<_Tp>) [with _Tp = void*, _Alloc =
SharedMemAlloc<std::_List_node <void*> >]'
shmcont.h:71: instantiated from here

/usr/lib/gcc/i386-redhat-linux/4.1.1/../../../../include/c++/4.1.1/
bits/stl_list.h:327:
error: conversion from 'const SharedMemAllo c<std::_List_node<void*>

' to

non-scalar type 'sharedMemAlloc<void*>' requested
============================================================

I noticed that in a new stl_list.h we have the following:
-----------------------------------------------------------
     typedef typename _Alloc::template rebind<_List_node<_Tp>

::other

       _Node_alloc_type;

     typedef typename _Alloc::template rebind<_Tp>::other
_Tp_alloc_type;

    Tp_alloc_type
     _M_get_Tp_allocator() const
     { return *static_cast<const _Node_alloc_type*>(&this-

_M_impl); }


     allocator_type
     get_allocator() const
     { return _M_get_Tp_allocator(); }
----------------------------------------------------------------

while in the old one:
----------------------------------------------------------------
typedef typename _Alloc::template rebind<_List_node<_Tp> >::other

     _Node_Alloc_type;
 allocator_type
     get_allocator() const
     { return allocator_type(*static_cast<const
_Node_Alloc_type*>(&this->_M_impl)); }
-----------------------------------------------------------------

I do not know how to change my declaration of the allocator to allow
conversion required by the new header file.

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