This function visits all the direct fields of the given cursor,
invoking the given \p visitor function with the cursors of each
visited field. The traversal may be ended prematurely, if
the visitor returns \c CXFieldVisit_Break.
\param T the record type whose field may be visited.
\param visitor the visitor function that will be invoked for each
field of \p T.
\param client_data pointer data supplied by the client, which will
be passed to the visitor each time it is invoked.
\returns a non-zero value if the traversal was terminated
prematurely by the visitor returning \c CXFieldVisit_Break.
\brief Visit the fields of a particular type.
This function visits all the direct fields of the given cursor, invoking the given \p visitor function with the cursors of each visited field. The traversal may be ended prematurely, if the visitor returns \c CXFieldVisit_Break.
\param T the record type whose field may be visited.
\param visitor the visitor function that will be invoked for each field of \p T.
\param client_data pointer data supplied by the client, which will be passed to the visitor each time it is invoked.
\returns a non-zero value if the traversal was terminated prematurely by the visitor returning \c CXFieldVisit_Break.