Return the position of the last occurrence of the specified character, if such an occurrence can be found in this string (on or before the optionally specified position if such a position is specified), and return npos otherwise.
character
position
npos
Declared in <bslstl_string.h>
<bslstl_string.h>
size_type rfind( wchar_t character, size_type position = npos) const;