std::ios_base::sync_with_stdio

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C++
 
输入/输出库
I / O操纵
C-风格的I / O
缓冲区
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Buffers
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basic_streambuf
basic_filebuf
basic_stringbuf
strstreambuf（过时了）
流
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Streams
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抽象
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Abstractions
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ios_base
basic_ios
basic_istream
basic_ostream
basic_iostream
文件I / O
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File I/O
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basic_ifstream
basic_ofstream
basic_fstream
字符串I / O
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basic_istringstream
basic_ostringstream
basic_stringstream
阵列的I / O
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streamoff
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iostream_category（C++11）
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std::ios_base
成员函数
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ios_base::ios_base
ios_base::~ios_base
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ios_base::flags
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ios_base::register_callback
ios_base::sync_with_stdio
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static bool sync_with_stdio( bool sync = true );

Sets whether the standard std::cin, std::cout, std::cerr, std::clog, std::wcin, std::wcout, std::wcerr and std::wclog C++ streams are synchronized to the standard stdin, stdout, stderr and stdlog C streams after each input/output operation.

For a standard stream str, synchronized with the C stream f, the following pairs of functions have identical effect:

1) std::fputc(f, c) and str.rdbuf()->sputc(c)
2) std::fgetc(f) and str.rdbuf()->sbumpc(c)
3) std::ungetc(c, f) and str.rdbuf()->sputbackc(c) In practice, this means that the C++ and the C streams use the same buffer, and therefore, can be mixed freely. In addition, synchronized C++ streams are guaranteed to be thread-safe (individual characters output from multiple threads may interleave, but no data races occur)

If the synchronization is turned off, the C++ standard streams are allowed to buffer their I/O independently, which may be considerably faster in some cases.

By default, all eight standard C++ streams are synchronized with their respective C streams.

It is implementation-defined if this function has any effect if called after some I/O occurred on the standard stream.

目录

[编辑] 参数

sync - the new synchronization setting

[编辑] 返回值

synchronization state before the call to the function

[编辑] 为例

#include <iostream>
#include <cstdio>
int main()
{
    std::cout.sync_with_stdio(false);
    std::cout << "a\n";
    std::printf("b\n");
    std::cout << "c\n";
}

Output: 

b
a
c

[编辑] 另请参阅
写入标准C的输出流stdout
（全局对象）的
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writes to the standard C output stream stdout
（全局对象）
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[edit]
写入标准的C错误流stderr，unbuffered
（全局对象）
Original:
writes to the standard C error stream stderr, unbuffered
（全局对象）
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[edit]
写入标准的C错误流stderr
（全局对象）
Original:
writes to the standard C error stream stderr
（全局对象）
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[edit]
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