Compiler warning when using vector of pointers

From: Adrian (nntp_at_bluedreamer.com)
Date: 10/31/04 

Date: Sun, 31 Oct 2004 17:03:04 +0000 (UTC)

Hi all,

I am getting a warning compiling the following code using Borland C++
Builder 6, but I dont think I am doing anything wrong. When using g++ I
get no warnings at all with a g++ -Wall -ansi -pedantic.

Now I usually assume the compiler is correct but in this case I am not sure.

push 1 gives the warning the other 2 go through fine.

The warning text is:-
"C:\temp>bcc32 a.cpp
Borland C++ 5.6.4 for Win32 Copyright (c) 1993, 2002 Borland a.cpp:
Warning W8030 a.cpp 24: Temporary used for parameter '__x' in call to
'_STL::vector<A *,_STL::allocator<A *> >::push_back(A * const &)' in
function main()
Turbo Incremental Link 5.66 Copyright (c) 1997-2002 Borland"

I cant see why a temporary is being created, what am I missing

TIA

--------------

#include <vector>

class A
{
   public:
     virtual ~A()=0;
   private:
};

A::~A()
{
}

class BA : public A
{
   public:
   private:
};

int main()
{
   std::vector<A *> fred;

   fred.push_back(new BA()); // push 1 Gives warning

   A *ptr=new BA();
   fred.push_back(ptr); // push 2
   fred.push_back(ptr=new BA()); // push 3

   return 0;
}

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