std::basic_stringbuf<CharT,Traits,Allocator>::setbuf (3) - Linux Manuals

std::basic_stringbuf<CharT,Traits,Allocator>::setbuf: std::basic_stringbuf<CharT,Traits,Allocator>::setbuf


std::basic_stringbuf<CharT,Traits,Allocator>::setbuf - std::basic_stringbuf<CharT,Traits,Allocator>::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

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