Scroll to navigation

std::basic_stringbuf::setbuf(3) C++ Standard Libary std::basic_stringbuf::setbuf(3)


std::basic_stringbuf::setbuf - std::basic_stringbuf::setbuf


virtual std::basic_streambuf<CharT, Traits>* setbuf( char_type* s, std::streamsize
n )

If s is a null pointer and n is zero, this function has no effect.

Otherwise, the effect is implementation-defined: some implementations do nothing,
while some implementations clear the std::string member currently used as the buffer
and begin using the user-supplied character array of size n, whose first element is
pointed to by s, as the buffer and the input/output character sequence.

This function is protected virtual, it may only be called through pubsetbuf() or
from member functions of a user-defined class derived from std::basic_stringbuf.


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

Return value



The deprecated stream buffer std::strstreambuf or the boost.IOStreams device
boost::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

// Run this code

#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';


3.14 (on GNU g++/libstdc++ and SunPro C++/roguewave)
<nothing> (on MS Visual Studio 2010, SunPro C++/stlport4, CLang++/libc++)

See also

pubsetbuf invokes setbuf()
(public member function of std::basic_streambuf<CharT,Traits>)