コード:

for( int i=0; i<MAX-1; i++ ) {
  for( int j=i+1; j<MAX; j++ ) {
      if(
          abs(objs[ i ].m_x - objs[ j ].m_x )*2
           + abs( objs[ i ].m_y - objs[ j ].m_y )*2 < 100
      ) {
          float tmpv = objs[ i ].m_vx;
              
          objs[ i ].m_vx = objs[ j ].m_vx;
          objs[ j ].m_vx = tmpv;
              
          tmpv = objs[ i ].m_vy;
          objs[ i ].m_vy = objs[ j ].m_vy;
          objs[ j ].m_vy = tmpv;
      }
  }
}                

コード:

#include <vector>
#include <algorithm>
#include <functional>
    
class TObj {
public:
        TObj() {}
        virtual ~TObj() {}
        virtual void draw() {}
};
    
class TPlayer: public TObj {
public:
        TPlayer() {}
        virtual ~TPlayer() {}
        virtual void draw() {}
};
    
int
main()
{
      using namespace std;
        
      TObj            objs[ 3 ];
      TPlayer         player;     
      vector<TObj*>   all;
      all.push_back( objs );
      all.push_back( &player );
    
      for( auto&& x:all ) { x->draw(); }
      
      return 0;
}
    
    
// end.  

コード:

#include <vector>
#include <algorithm>
#include <functional>

class TObj {
public:
    TObj() {}
    virtual TObj() {}
    virtual void draw() {}
};

class TPlayer: public TObj {
public:
    TPlayer() {}
    virtual TPlayer() {}
    virtual void draw() {}
};

int
main()
{
	std::vector<TObj*> objs;

	objs.push_back( new TObj() );
	objs.push_back( new TObj() );
	objs.push_back( nrew TPlayer() );

#if 0
	for( auto&& x:objs ) {
		x->draw();
	}
#else
	for_each( objs.begin(), objs.end(), std::mem_fun(TObj::draw) );
#endif
}