std::streamoff

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C++ Standard Library
Language Utilities library Strings library Containers library Algorithms library Iterators library Numerics library Input/output library Localizations library Regular expressions library (C++11) Atomic operations library (C++11) Thread support library (C++11)
Input/output library
I/O manipulators C-style I/O Buffers basic_streambuf basic_filebuf basic_stringbuf strstreambuf (deprecated) Streams Abstractions ios_base basic_ios basic_istream basic_ostream basic_iostream File I/O basic_ifstream basic_ofstream basic_fstream String I/O basic_istringstream basic_ostringstream basic_stringstream Array I/O istrstream (deprecated) ostrstream (deprecated) strstream (deprecated) Types streamoff streamsize fpos Error category interface iostream_category (C++11) io_errc (C++11)

Defined in header <ios>
typedef /*unspecified*/ streamoff;

The type std::streamoff is a signed integral type of sufficient size to represent the maximum possible file size supported by the operating system. Typically, this is a typedef to long long.

It is used to represent offsets from stream positions (values of type std::fpos). A std::streamoff value of -1 is also used to represent error conditions by some of the I/O library functions.

[edit] Relationship with std::fpos

• the difference between two std::fpos objects is a value of type std::streamoff

• a value of type std::streamoff may be added or subtracted from std::fpos yielding a different std::fpos.

• a value of type std::fpos is implicitly convertible to std::streamoff (the conversion results in the offset from the beginning of the file.

• a value of type std::fpos is constructible from a value of type std::streamoff

[edit] See also

fpos	represents absolute position in a stream or a file (class template)
seekg	sets the input position indicator (public member function of std::basic_istream)
seekp	sets the output position indicator (public member function of std::basic_ostream)