Re: [Boost-users] A question about shared_ptr(Zhuo Hao)

But consider the following code: #include<iostream> using namespace std; class CMutex{};//Hide all the implementations for convience template<class Y> void world(Y * p) { } void hello(int *x){ } int main(){ hello(0); world<CMutex>(0); return 1; } It compiles and runs without problems.So you see I can pass zero as a pointer to Y, and as a pointer to int. That's OK. I wonder how it is implemented that we cannot pass zero as a pointer to Y in the constructor of shared_ptr. Thanks Zhuo Hao On 14/07/06, Tommy Hinks replied: You can't pass 0 because the Type passed must be an Investment*, not just a type that could be cast to one. This is why you have to explicitly cast it yourself.