[GiNaC-list] Getting a pointer to an element in a list?

[John Pye]

Hi all

A hopefully pretty simple question about lists in GiNaC. I have a little
fragment of code like this:

class SymbolicSystem{

private:
   GiNaC::lst F;

public:
   const ex * getExpressionPtr(const unsigned &i) const{
      *return* &(F[i]);
   }
}

Is there something about the implementation of the operator[] in
GiNaC::list that stops me from being able to do this? GCC gives me a
warning, like this:

warning: taking address of temporary

This might be an elementary C++ mistake, but just in case, I thought I'd
ask.

Cheers
JP