FUNCDESC

This structure is used to define a function description.

At a Glance

Syntax

typedef struct tagFUNCDESC {
MEMBERID memid;
/* [size_is(cScodes)] */ SCODE RPC_FAR *lprgscode;
/* [size_is(cParams)] */ ELEMDESC __RPC_FAR *lprgelemdescParam;
FUNCKIND funckind;
INVOKEKIND invkind;
CALLCONV callconv;
short cParams;
short cParamsOpt;
short oVft;
short cScodes;
ELEMDESC elemdescFunc;
WORD wFuncFlags;
} FUNCDESC;

Members

memid

Function member identifier.

lprgscode

lprgelemdescParam

funckind

Specifies whether the function is virtual, static, or dispatch-only.

invkind

Invocation kind. Indicates if this is a property function, and if so, what kind.

callconv

Specifies the function’s calling convention.

cParams

Count of total number of parameters, both required and optional.

cParamsOpt

Count of optional parameters.

ovft

For FUNC_VIRTUAL, specifies the offset in the VTBL.

cScodes

Count of permitted return values.

elemdescFunc

Contains the return type of the function.

wFuncFlags

Definition of flags follows.

Remarks

The cParamsOpt member specifies the form of optional parameters accepted by the function, as follows:

• A value of 0 specifies that no optional arguments are supported.
  
  
• A value of –1 specifies that the methods last parameter is a pointer to a safe array of variants. Any number of variant arguments greater than cParams –1 must be packaged by the caller into a safe array and passed as the final parameter. This array of optional parameters must be freed by the caller after control is returned from the call.
  
  
• Any other number indicates that the last n parameters of the function are variants and do not need to be specified by the caller explicitly. The parameters left unspecified should be filled in by the compiler or interpreter as variants of type VT_ERROR with the value DISP_E_PARAMNOTFOUND.

For 16-bit systems (Macintosh), the members cScodes and lprgscode store the count and the set of errors that a function can return. If cScodes = –1, then the set of errors is unknown. If cScodes = –1, or if cScodes = 0, then lprgscodeis undefined.