STL map iterator with templates parameters

ROOT
1

Hello,

I have the following code with a template class and a STL map but it gives me an error.

The code :

[code]#include
using namespace std;

template <typename Key, class Object>
class TObjectFactory
{
public:

typedef Object *(*Creator)();

map<Key, Creator> fRegisteredCreator;

bool Register(Key key, Creator creator)
{
  if( fRegisteredCreator.find(key) != fRegisteredCreator.end() )
    return false;

  fRegisteredCreator.insert(pair<Key, Creator>(key, creator));
  return true;
}


Object* Create(Key key)
{
  Object *object;
  Creator creator;
  map<Key, Creator>::iterator it;

  it = fRegisteredCreator.find(key);
  if(it == fRegisteredCreator.end())
    return NULL;

  creator = (*it).second;
  object = (*creator)();
  return object;
}

};[/code]

The error:
error: expected `;’ before ‘it’

He seems to ignore my iterator declaration. Is root incompatible with the STL&Templates?

2

[quote=“f56bre”]Hello,

I have the following code with a template class and a STL map but it gives me an error.

The code :

[code]#include
using namespace std;

template <typename Key, class Object>
class TObjectFactory
{
public:

typedef Object *(*Creator)();

map<Key, Creator> fRegisteredCreator;

bool Register(Key key, Creator creator)
{
  if( fRegisteredCreator.find(key) != fRegisteredCreator.end() )
    return false;

  fRegisteredCreator.insert(pair<Key, Creator>(key, creator));
  return true;
}


Object* Create(Key key)
{
  Object *object;
  Creator creator;
  map<Key, Creator>::iterator it;

  it = fRegisteredCreator.find(key);
  if(it == fRegisteredCreator.end())
    return NULL;

  creator = (*it).second;
  object = (*creator)();
  return object;
}

};[/code]

The error:
error: expected `;’ before ‘it’

He seems to ignore my iterator declaration. Is root incompatible with the STL&Templates?[/quote]
One of the problem I see in your code is that you use

without typename key word.
iterator may be interpreted as a static member of the class map<Key, Creator>. To make it clear you need to write

It has nothing to do with ROOT, it is just C++.

P.S. You may want to define something like typedef map<Key, Creator> container_t; Otherwise you will be forced always write definition of your map.

3

Perfect, it compiles now,

thank you very much anar.

4

[quote=“f56bre”]Perfect, it compiles now,

thank you very much anar.[/quote]
:wink: