Instantiation of fpos used to represent positions in narrow-oriented streams.
Objects of this class support construction and conversion from int, and allow consistent conversions to/from streamoff values (as well as being added or subtracted a value of this type).
Two objects of this type can be compared with operators == and !=. They can also be subtracted, which yields a value of type streamoff.
streampos and wstreampos are synonyms: both are typedefs of fpos<mbstate_t>.