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

On 7/16/06, Delfin Rojas <drojas@moodlogic.com> wrote:

template <class U> class P { public: template <class V> P(V * v) : u(v) {}

private: U *u; };

Now "P<CMutex> p1(0);" will not compile but "P<CMutex> p1(new CMutex);" will.

I believe this is due to the fact that in C++ it is illegal for the compiler to do more than one implicit cast. In this case it would have to implicitly cast from <int>(0) to <V *>(0) and then implicitly cast again from <V *>(0) to <U *>(0). Jon