Here is my attempt at implementing a object factory. The purpose of this
is to replace a large switch statement in a factory class with the
functors. I get an error at line 88, marked, "expected primary-expression
before ')' token". I am using Modern C++ Design chapter 8 as a guide.
Stephen
---------------------
#include <map>
#include <iostream>
namespace tool
{
namespace component
{
class Component;
}
namespace infrastructure
{
class Component_Factory
{
public:
typedef component::Component* (*CreateComponentCallback)();
bool RegisterComponent ( int component_id,
CreateComponentCallback call_func )
{
return m_callbacks.insert ( CallbackMap::value_type ( component_id,
call_func ) ).second;
}
bool UnregisterComponent ( int component_id ) {
return m_callbacks.erase ( component_id ) == 1;
}
component::Component* CreateComponent ( int component_id ) {
CallbackMap::const_iterator pos = m_callbacks.find ( component_id );
if ( pos == m_callbacks.end() )
{
std::cerr << "Unknown Component ID" << std::endl; abort();
}
return (pos->second)();
}
private:
typedef std::map<int, CreateComponentCallbackCallbackMap;
CallbackMap m_callbacks;
};
}
namespace component
{
class Component
{};
class Apple : public Component
{
public:
static const int ID = 1;
Component* operator()()
{
return new Apple;
}
};
class Blueberry : public Component
{
public:
static const int ID = 5;
Component* operator()()
{
return new Blueberry;
}
};
}
}
int main (int, char**)
{
tool::infrastructure::Component_Factory fact_ref;
/* LINE 88 */
fact_ref.RegisterComponent ( tool::component::Apple::ID,
tool::component::Apple );
fact_ref.UnregisterComponent ( tool::component::Apple::ID );
return 0;
}
