Improper use of std::map?

OK, I have the bellow code which give me an error (see the comment).

#pragma once

#include <map>
#include <string>
using std::string;

class Actor
{
     public:
         unsigned int hp;

         Actor( const unsigned int _hp )
             : hp( _hp )
         {
         }

         Actor()
             : hp( 0 )
         {
         }

         virtual ~Actor();

         virtual void act() = 0;
};

typedef std::map<string,Actor*> ActT;
typedef ActT::iterator ActIt;
ActT actors;

class Player : public Actor
{
     public:
         Player( const unsigned int _hp )
             : Actor( _hp )
         {
         }

         Player()
             : Actor( 0 )
         {
         }

         void act();
};

// TESTING //
actors[ "Player1" ] = new Player( 100 ); // ERROR: Expected
conversion, constructor, destructor before "=".

class Enemy : public Actor
{
     public:
         void act();
};

Is this not proper use of the sdt::map? I was thinking it's EXACTLY
the right use (or that it's exactly what I want to use), but I can't
figure out this error. Thanks in advance.

{ Isn't it because the expression statement is in the namespace scope?
   Enclose it in a function body, and that gives me no error. -mod/sk }

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