[Boost-users] shared_ptr and polymorphism

Subject: [Boost-users] shared_ptr and polymorphism
From: Abderrahmane Madani (abderrahmane.madani_at_[hidden])
Date: 2010-02-23 04:36:17

Just a little problem that I can't fix. 
Suppose that I have these four classes 

class B {}; 

class D1: public B {}; 

class D2: public B {}; 

class E: public D1 {}; 

this test: 

void foo(D1 *) {} 
void foo(D2 *) {} 

int main() 
{ 
E *e = new E; 
foo(e); 
return 0; 
} 
work just fine 

but this one 

void foo(shared_ptr<D1>) {} 
void foo(shared_ptr<D2>) {} 

int main() 
{ 
shared_ptr<E> e(new E); 
foo(e); 
return 0; 
} 
the compiler say that the foo(boost::shared_ptr<E>&)' is ambiguous. 

Please, can someone help me to understand why and how can I fix this problem without changing the functions name. 
Thanks 

Boost 1.35 
GCC 4.4.1 

regards