C++ template method forward declaration -

i'm having little problem classes. have 2 classes both use template methods, therefore have put in header. here example. i'd compile without "forward declaration incomplete" problem. understand wrong can't figure how correct this. thank guys.

class.h

    class a;     class b;      class     {         b *foo;          template <class t>         void func()         {             foo->fanc();            }     }      class b     {        *foo;         void fanc();         template <class t>        void osef()        {             foo->func<int>();        }     } 

you have circular dependence. can not declare object of incomplete class. can solve declaring either pointers or references incomplete class.

class {     b* foo; 

or

class {     b& foo; 

on later case have initialize reference member initialization list of constructor.

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if using pointer should move definition of memeber function after definition of incomplte class.

class a; class b;  class {     b* foo;     template <class t>     void func(); };  class b {   // ... };  template <class t> inline void a::func() ^^^^^^                   // if need include header in more 1 source file. {     foo->fanc();    }