"no matching function for call error" when calling constructor from helper function in g++

I have a constructor

A::A(const Name& n,const IRole& r)
: ...
{ }

And helper function that uses the contructor

AP<A> A::Create(const Name& n, const IRole& r)
{
    return new A(n,r);
}

And g++ gives me error messages when 开发者_StackOverflowI compile this code.

error: no matching function for call to ‘AIR::AP<AIR::A>::AP(AIR::AP<AIR::A>)’
 note: candidates are:   AIR::AP<T>::AP(AIR::AP<U>&) [with U = AIR::A, T = AIR::A]
 note:                   AIR::AP<T>::AP(AIR::AP<T>&) [with T = AIR::A]
 note:                   AIR::AP<T>::AP(T*) [with T = AIR::A]
error:   initializing temporary from result of ‘AIR::AP<T>::AP(T*) [with T = AIR::A]’

What's wrong with this code?

ADDED

AP<A> A::Create(const Name& n, const IRole& r)
{
    AP<A> port(new A(n,r));
    return port; 
}

Seems to solve this issue.

You are not showing the call to Create; is that trying to copy the result of the call into a new variable? Note that only non-const AP<T> objects can be copied, and so temporaries (which can't bind to non-const references) are not copyable with your current definitions.