\brief If the cursor points to a selector identifier in a objc method or
message expression, this returns the selector index.
After getting a cursor with \see clang_getCursor, this can be called to
determine if the location points to a selector identifier.
\returns The selector index if the cursor is an objc method or message
expression and the cursor is pointing to a selector identifier, or -1
otherwise.
\brief If the cursor points to a selector identifier in a objc method or message expression, this returns the selector index.
After getting a cursor with \see clang_getCursor, this can be called to determine if the location points to a selector identifier.
\returns The selector index if the cursor is an objc method or message expression and the cursor is pointing to a selector identifier, or -1 otherwise.