std::basic_streambuf::pubsetbuf
basic_streambuf<CharT, Traits>* pubsetbuf( char_type* s, std::streamsize n ) | (1) | ? |
|---|---|---|
protected: virtual basic_streambuf<CharT, Traits>* setbuf( char_type* s, std::streamsize n ) | (2) | ? |
1%29次电话setbuf(s, n)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，以允许用用户提供的数组删除或替换受控字符序列%28(缓冲区%29)，或用于任何其他特定于实现的目的。
参数
s | - | pointer to the first byte in the user-provided buffer |
|---|---|---|
n | - | the number of bytes in the user-provided buffer |
返回值
1%29setbuf(s, n)
2%29this
例
提供10K的阅读缓冲区。在Linux上，可以使用strace实用程序来观察实际读取的字节数。
二次
#include <fstream>
#include <iostream>
#include <string>
int main()
{
int cnt = 0;
std::ifstream file;
char buf[10241];
file.rdbuf()->pubsetbuf(buf, sizeof buf);
file.open("/usr/share/dict/words");
for (std::string line; getline(file, line);) {
cnt++;
}
std::cout << cnt << '\n';
}二次
另见
setbuf virtual | attempts to replace the controlled character sequence with an array (virtual protected member function of std::basic_stringbuf) |
|---|---|
setbuf virtual | provides user-supplied buffer or turns this filebuf unbuffered (virtual protected member function of std::basic_filebuf) |
setbuf virtual | attempts to replace the controlled character sequence with an array (virtual protected member function of std::strstreambuf) |
setbuf | sets the buffer for a file stream (function) |
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