G_CHECK(2)              Demeter Software               G_CHECK(2)



NAME
     g_check - send the generic check message to an object.

SYNOPSIS
     int Universal:: _g__c_h_e_c_k ( char* objClassName )


DESCRIPTION
     _g__c_h_e_c_k checks whether the receiver is  a  legal  object  of
     class  _o_b_j_C_l_a_s_s_N_a_m_e.  If  _o_b_j_C_l_a_s_s_N_a_m_e  is not provided, the
     first class in the current class  dictionary  is  used.  The
     receiving  object  must be a tree object. That is, it cannot
     have any cycles or shared subobjects.  _g__c_h_e_c_k is a  generic
     method  implemented  at class Universal and inherited by any
     user class.


ERROR MESSAGES
     If  the  receiving  object  is  a  legal  object  of   class
     _o_b_j_C_l_a_s_s_N_a_m_e,  _g__c_h_e_c_k displays the message "GCHECK Success:
     this is a legal object of type  _o_b_j_C_l_a_s_s_N_a_m_e  ".  Otherwise,
     three error messages are displayed.


     Diagnostic
               An explanation of the error.

     Production stack dump
               A listing, in reverse order, of the productions in
               the  grammar that led to the point where the error
               occurred.

     Error condition
               The message "GCHECK Error: this  is  NOT  a  legal
               object of type _o_b_j_C_l_a_s_s_N_a_m_e " is displayed.

EXAMPLE
     Here is an example of how to use _g__c_h_e_c_k .

     Compound* iCompound = new Compound();
     iCompound = someCompoundInstantiatingFunction();

     if( iCompound->g_check() )
        exit( -1 );

     Of course, in this example we could have used  g_parse.  But
     since  a  successful  send of g_parse always returns a legal
     object, sending g_check becomes  unnecessary.  This  example
     shows that _g__c_h_e_c_k is most useful when instantiating objects
     with means other than g_parse.





Demeter            Last change: 2 October 1991                  1






G_CHECK(2)              Demeter Software               G_CHECK(2)



SEE ALSO
     g_parse(2), g_equal(2), g_copy(2)


REFERENCES
     _U_s_e_r _M_a_n_u_a_l _f_o_r _T_h_e _C++ _D_e_m_e_t_e_r
     Walter L. Hursch
     Northeastern University, 1993

     _T_h_e _A_n_n_o_t_a_t_e_d _C++ _R_e_f_e_r_e_n_c_e _M_a_n_u_a_l
     Margaret A. Ellis and Bjarne Stroustrup
     Addison-Wesley, 1990

     _C++ _P_r_i_m_e_r
     Stanley B. Lippman
     Addison-Wesley, 1989







































Demeter            Last change: 2 October 1991                  2