istringstream.cpp

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#include <iomanip>    // for setw
#include <ios>        // for dec, hex, oct, right, showbase
#include <iostream>   // for endl, wcout, wostream
#include <locale>     // for isspace()
#include <sstream>    // for strstream, wistringstream
#include <string>     // for wstring
 
#include <examples.h>
 
 
int main ( )
{
    try {
 
        // create a read/write stream object
        std::wistringstream in (std::ios::in | std::ios::out);
 
        // associate the ostream object's buffer with the ifstream object
        std::wostream out (in.rdbuf ());
 
        // enable exceptions in both streams
        in.exceptions (std::ios::badbit);
        out.exceptions (std::ios::failbit | std::ios::badbit);
 
        // write string into out
        out << L"Il avait l'air heureux." << std::endl;
 
        // seek to the beginning of the stream
        in.seekg (0);
 
        wchar_t c;
 
        // output each space-separated word on a separate line
        while (in.get (c)) {
            if ((std::isspace)(c, in.getloc ())) 
                std::wcout << std::endl;
            else
                std::wcout.put(c);
        }
 
        std::wcout << std::endl;
 
        // clear stream state, failbit | eofbit set by last call to get ()
        in.clear ();
 
        // move back to the beginning of the stream
        in.seekg (0); 
 
        wchar_t buf [40];
 
        // guard against buffer overflow
        in.width (sizeof buf);
 
        // set right justification
        std::wcout << std::right;
 
        // does the same thing as the previous code
        // output each word on a separate line in a field of width 10
        while (in >> buf) {
            std::wcout.width (10);
            std::wcout << buf << std::endl;
        }
    
        std::wcout << std::endl;
 
        // clear flags, last in >> buf set fail bit
        // because of a newline at end of string
        in.clear (); 
 
        // output the base info before each integer
        out << std::showbase;
 
        std::wostream::pos_type pos= out.tellp ();
 
        const long l = 10;
        
        // output l in hex with a field with of 10 
        out << std::hex << std::setw (10) << l << std::endl;
 
        // output l in oct with a field with of 10
        out << std::oct << std::setw (10) << l << std::endl;
 
        // output l in dec with a field with of 10
        out << std::dec << std::setw (10) << l << std::endl;
 
        // move back to the beginning of the stream
        in.seekg (0);
 
        // output the entire stream
        std::wcout << in.rdbuf () << std::endl;
 
        // clear the flags 
        in.clear (); 
 
        // seek the input sequence to pos  
        in.seekg (pos);
  
        in.unsetf (std::ios::basefield);
 
        int a, b, d;
 
        // read the previous outputted integer
        in >> a >> b >> d;
 
        // output 3 times 10
        std::wcout << a << std::endl << b << std::endl << d << std::endl;
 
    }
    catch (std::ios::failure &e) {
        std::wcerr << e.what () << std::endl;
    }
 
    return 0;
}