View source for cpp/io/streamoff

{{cpp/title | streamoff}}
{{cpp/io/navbar}}
{{dcl begin}}
{{dcl header | ios}}
{{dcl | 1=
typedef /*implementation-defined*/ streamoff;
}}
{{dcl end}}

The type {{tt|std::streamoff}} is an implementation-defined {{rev inl|since=c++11|signed integral}} type of sufficient size to represent the maximum possible file size supported by the operating system. {{rev inl|since=c++11|Typically, this is an alias for {{c|long long}}.}}

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

===Relationship with std::fpos===
* the difference between two {{lc|std::fpos}} objects is a value of type {{tt|std::streamoff}}

* a value of type {{tt|std::streamoff}} may be added or subtracted from {{lc|std::fpos}} yielding a different {{lc|std::fpos}}.

* a value of type {{lc|std::fpos}} is implicitly convertible to {{tt|std::streamoff}} (the conversion result is the offset from the beginning of the file).

* a value of type {{lc|std::fpos}} is constructible from a value of type {{tt|std::streamoff}}

===See also===
{{dsc begin}}
{{dsc inc | cpp/io/dsc fpos}}
{{dsc inc | cpp/io/basic_istream/dsc seekg}}
{{dsc inc | cpp/io/basic_ostream/dsc seekp}}
{{dsc end}}

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