| I/O manipulators | ||||
| Print functions(C++23) | ||||
| C-style I/O | ||||
| Buffers | ||||
(C++23) | ||||
(C++98/26*) | ||||
(C++20) | ||||
| Streams | ||||
| Abstractions | ||||
| File I/O | ||||
| String I/O | ||||
| Array I/O | ||||
(C++23) | ||||
(C++23) | ||||
(C++23) | ||||
(C++98/26*) | ||||
(C++98/26*) | ||||
(C++98/26*) | ||||
| Synchronized Output | ||||
(C++20) | ||||
| Types | ||||
| Error category interface | ||||
(C++11) | ||||
(C++11) |
| Public member functions | ||||
(C++11) | ||||
(C++11) | ||||
(C++20) | ||||
| Protected member functions | ||||
basic_stringbuf::setbuf | ||||
| Non-member functions | ||||
(C++11) | ||||
| Exposition-only member functions | ||||
protected: virtualstd::basic_streambuf<CharT, Traits>* setbuf( char_type* s,std::streamsize n) | ||
Ifs is a null pointer andn is zero, this function has no effect.
Otherwise, the effect is implementation-defined: some implementations do nothing, while some implementations clear thestd::string member currently used as the buffer and begin using the user-supplied character array of sizen, whose first element is pointed to bys, as the buffer and the input/output character sequence.
This function is protected virtual, it may only be called throughpubsetbuf() or from member functions of a user-defined class derived fromstd::basic_stringbuf.
Contents |
| s | - | pointer to the first CharT in the user-provided buffer or null |
| n | - | the number of CharT elements in the user-provided buffer or zero |
this
The deprecated stream bufferstd::strstreambuf or the boost.IOStreams deviceboost::basic_array may be used to implement I/O buffering over a user-provided char array in portable manner.
Test for the stringstream's setbuf functionality.
#include <iostream>#include <sstream> int main(){std::ostringstream ss;char c[1024]={}; ss.rdbuf()->pubsetbuf(c,1024); ss<<3.14<<'\n';std::cout<< c<<'\n';}
Output:
3.14 (on GNU g++/libstdc++ and SunPro C++/roguewave)<nothing> (on MS Visual Studio 2010, SunPro C++/stlport4, CLang++/libc++)
| invokessetbuf() (public member function of std::basic_streambuf<CharT,Traits>)[edit] |
