From cppreference.com
Defined in header
typedef/*implementation-defined*/streamoff;The type std::streamoff is an implementation-defined signed integral(since C++11) type of sufficient size to represent the maximum possible file size supported by the operating system. Typically, this is an alias for longlong.(since C++11)
It is used to represent offsets from stream positions (values of type
). A std::streamoff value constructed from -1 is also used to represent error conditions by some of the I/O library functions.
Relationship with std::fpos
the difference between two
objects is a value of type std::streamoff
a value of type std::streamoff may be added or subtracted from
yielding a different
.
a value of type
is implicitly convertible to std::streamoff (the conversion result is the offset from the beginning of the file).
a value of type
is constructible from a value of type std::streamoff
See also
represents absolute position in a stream or a file
(class template)
sets the input position indicator
(public member function of std::basic_istream<CharT,Traits>)
sets the output position indicator
(public member function of std::basic_ostream<CharT,Traits>)