std::basic_streambuf::seekoff
pos_type pubseekoff( off_type off, std::ios_base::seekdir dir, std::ios_base::openmode which = ios_base::in | ios_base::out ); | (1) | |
|---|---|---|
protected: virtual pos_type seekoff( off_type off, std::ios_base::seekdir dir, std::ios_base::openmode which = ios_base::in | ios_base::out ); | (2) | |
设置相对于其他位置的输入和/或输出序列的位置指示符。
1%29次电话seekoff(off, dir, which)最派生的类。
2%29此函数的基类版本没有任何影响。派生类可以重写此函数以允许位置指示器的相对定位。
参数
off | - | relative position to set the position indicator to. | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
dir | - | defines base position to apply the relative offset to. It can be one of the following constants: Constant Explanation beg the beginning of a stream end the ending of a stream cur the current position of stream position indicator | Constant | Explanation | beg | the beginning of a stream | end | the ending of a stream | cur | the current position of stream position indicator |
Constant | Explanation | |||||||||
beg | the beginning of a stream | |||||||||
end | the ending of a stream | |||||||||
cur | the current position of stream position indicator | |||||||||
which | - | defines which of the input and/or output sequences to affect. It can be one or a combination of the following constants: Constant Explanation in affect the input sequence out affect the output sequence | Constant | Explanation | in | affect the input sequence | out | affect the output sequence | ||
Constant | Explanation | |||||||||
in | affect the input sequence | |||||||||
out | affect the output sequence |
注
并非所有参数组合都可能有效，请参阅seekoff关于细节。
返回值
1%29seekoff(off, dir, which)...
2%29由位置指示器定义的最终绝对位置。基类版本返回pos_type(off_type(-1))...
例
另见
pubseekpos | invokes seekpos() (public member function) |
|---|---|
seekoff virtual | repositions the file position, using relative addressing (virtual protected member function of std::basic_filebuf) |
seekoff virtual | repositions the next pointer in the input sequence, output sequence, or both, using relative addressing (virtual protected member function of std::basic_stringbuf) |
seekoff virtual | repositions the next pointer in the input sequence, output sequence, or both, using relative addressing (virtual protected member function of std::strstreambuf) |
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