Doubt on correctnes of code

[Goedson Teixeira Paixao <goedson@debian.org>]

[ Please CC: me in the replies since I'm not subscribed to this list ] 

Hello,

The code below is compiled fine by g++-2.95 while g++-3.3 (version 3.3.1-1)
fails with the following message:

/home/goedson/teste.cc: In function `int main(int, char**)':
/home/goedson/teste.cc:22: error: conversion from `BClass' to `B*' is ambiguous
/home/goedson/teste.cc:16: error: candidates are: BClass::operator B*()
/home/goedson/teste.cc:9: error:                 AClass::operator A*()

My doubt is. What version of g++ is right? Is the code correct or, by
the C++ standard there is really an ambiguity?

Thanks in advance for any help,
Goedson


/////////// Code starts here ////////////////////////

typedef struct _A A;
typedef struct _A B;

void some_function(B *b);

class AClass {

public:
  operator A*() { return 0;}

};

class BClass :public AClass {

public:
  operator B*() { return 0;}

};

int main(int argc, char **argv) {
  BClass b;
  some_function(b);
}