C++ Programming :: use of undefined type????


	use of undefined type???? I have two classes(class A, class main). class main uses a pointer to class A and class A uses a global pointer to main. My problem is I keep getting these errors: :( a.h(12) : error C2027: use of undefined type 'main' a.h(4) : see declaration of 'main' a.h(12) : error C2227: left of '->SomeDriver' must point to class/ struct/union/generic type How do I fix this? Thx ahead of time. ******** #include "main.h" #include "A.h" main g_main = NULL; int _tmain(int argc, _TCHAR argv[]) { g_main = new main; g_main->a = new A; g_main->a->Print(); g_main->a->SomeFunction(); return 0; } ********* #ifndef MAIN_H #define MAIN_H class A; class main { public: void SomeDriver() { printf ("driver called\n"); } void PrintA() { a->Print(); } A a; }; extern main g_main; #endif ***** #ifndef A_H #define A_H class main; class A { public: void SomeFunction() { g_main->SomeDriver(); } void Print() { printf ("Characters: a\n"); } }; #endif Anonymous Infidel - Aborted Islam with a hanger wrote: > I have two classes(class A, class main). class main uses a pointer to > class A and class A uses a global pointer to main. My problem is I > keep getting these errors: :( > a.h(12) : error C2027: use of undefined type 'main' > a.h(4) : see declaration of 'main' > a.h(12) : error C2227: left of '->SomeDriver' must point to class/ > struct/union/generic type > How do I fix this? First off, you should probably rename your class from 'main' to smth else. 'main' is the name of the function in your program that starts its execution. > Thx ahead of time. > ****** > #include "main.h" > #include "A.h" > main g_main = NULL; > int _tmain(int argc, _TCHAR argv[]) There is no standard function _tmain. - Hide quoted text - > { > g_main = new main; > g_main->a = new A; > g_main->a->Print(); > g_main->a->SomeFunction(); > return 0; > } > ********* > #ifndef MAIN_H > #define MAIN_H > class A; > class main > { > public: > void SomeDriver() > { > printf ("driver called\n"); > } > void PrintA() > { > a->Print(); Class 'A' hasn't been defined here yet. Consider pulling this function out of the class definition into the translation unit. > } > A a; > }; > extern main g_main; > #endif > ******* > #ifndef A_H > #define A_H > class main; > class A > { > public: > void SomeFunction() > { > g_main->SomeDriver(); Although your 'A.h' is supposedly included after your 'main.h', if it weren't, 'g_main' is undefined here. Consider pulling this function out of the class definition into a translation unit. > } > void Print() > { > printf ("Characters: a\n"); > } > }; > #endif Consider separating declarations and implementations of class member functions. It's always a good idea for beginners. V -- Please remove capital 'A's when replying by e-mail I do not respond to top-posted replies, please don't ask On 6/6/2007 3:59 PM, Anonymous Infidel - Aborted Islam with a hanger wrote: > I have two classes(class A, class main). class main uses a pointer to > class A and class A uses a global pointer to main. My problem is I > keep getting these errors: :( > a.h(12) : error C2027: use of undefined type 'main' > a.h(4) : see declaration of 'main' > a.h(12) : error C2227: left of '->SomeDriver' must point to class/ > struct/union/generic type > How do I fix this? > [code snipped] see one of his other posts. What's wrong with you? Do you read answers to your posts? S. -- Stefan Naewe stefan dot naewe at atlas-elektronik dot com Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html Plain text mails only, please http://www.expita.com/nomime.html On Jun 6, 7:08 am, Stefan Naewe <nos@please.net> wrote: - Hide quoted text - > On 6/6/2007 3:59 PM, Anonymous Infidel - Aborted Islam with a hanger wrote: > > I have two classes(class A, class main). class main uses a pointer to > > class A and class A uses a global pointer to main. My problem is I > > keep getting these errors: :( > > a.h(12) : error C2027: use of undefined type 'main' > > a.h(4) : see declaration of 'main' > > a.h(12) : error C2227: left of '->SomeDriver' must point to class/ > > struct/union/generic type > > How do I fix this? > > [code snipped] see one of his other posts. > What's wrong with you? > Do you read answers to your posts? Yes.