c++ - How to keep track of multiple object instances? -

i made base class object track instances of objects. want log in file so:

object name: number of instances 

here base class:

template <class t> class countedobj { public:    countedobj()    {         // write name of derived class , counter log    }     countedobj(const countedobj& obj)    {        // write name of derived class , counter log    }     ~countedobj()     {        // write name of derived class , counter log    } private:    int counter;    mylogger log; }; 

my problem want print name of class inherit countedobj, can't use typeid inside constructor.

is there alternative log object allocated , deallocated ?

you didn't specified how use countedobj. assume this:

class foo: public countedobj<foo> { }; 

if derive further foo, counter unable differentiate between foo, , derived classes, suppose want print "foo" name derived classes. if want differentiate between these classes, different solution needed (i'll delete answer if that's case).

(or maybe can derive again countedobj: class fooderived: public foo, public countedobj<fooderived> { };, way, fooderived counted both fooderived , foo)

so, can use typeid way:

template <typename t> class countedobj {     public:         countedobj() {             counter++;             printf("%s: %d\n", typeid(t).name(), counter);         }     private:         static int counter; // static needed }; 

if don't output typeid().name(), can add static name-query function foo:

template <typename t> class countedobj {     public:         countedobj() {             counter++;             printf("%s: %d\n", t::name(), counter);         }          ... };  class foo: public countedobj<foo> {     public:         static const char *name() {             return "foo";         } };