strstreambuf.cpp

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#include <iomanip>     // for setw
#include <ios>         // for dec, ends
#include <iostream>    // for cerr, cout
#include <strstream>   // for istream, ostrstream
 
#include <examples.h>
 
 
int main ()
{
    // create a write-only stream object
    std::ostrstream out;
 
    // tie the istream object to the ostrstream object
    std::istream in (out.rdbuf ());   
 
    // output to out
    out << "Anticonstitutionnellement is a big word!!!\n";
 
    // create a NTBS 
    const char s[] ="Le rat des villes et le rat des champs.";
 
    // output the NTBS
    out << s << '\n';
 
    // (try to) resize the buffer
    if (out.rdbuf ()->pubsetbuf (0, 128L))
        std::cout << "Successfully allocated buffer.\n";
    else
        std::cerr << "Failed to allocate buffer.\n";
 
    // output the contents of the buffer to standard output
    std::cout << in.rdbuf ();
 
    // format a number into out
    out << std::dec              // decimal base
        << std::setfill ('#')    // set fill character
        << std::setw (16)        // set field width
        << 0x100 << '\n';        // format
  
    // output the content of the input sequence to standard output
    std::cout << in.rdbuf( ) << '\n';
 
    // number of elements in the output sequence
    const std::streamsize pcount = std::streamsize (out.rdbuf ()->pcount ());
 
    std::cout << "Buffer size is " << pcount << '\n';
 
    // (try to) resize the buffer
    if (out.rdbuf ()->pubsetbuf (0, pcount * 2L))
        std::cout << "\nSuccessfully resized buffer to " << pcount * 2 << '\n';
    else
        std::cerr << "\nFailed to resize buffer to " << pcount * 2 << '\n';
 
    // NUL-terminate the character array before streaming it out
    out << std::ends;
 
    // output the contents of the streambuf object associated with out
    std::cout << out.rdbuf ()->str ();
 
    // unfreeze the streambuf so it cleans up its allocated memory
    out.rdbuf ()->freeze (false);
 
    return 0;
}