examples/manual/codecvt.cpp

/**************************************************************************
 *
 * codecvt.cpp - Example program of codecvt facet. 
 *
 * $Id$
 *
 ***************************************************************************
 *
 * Licensed to the Apache Software  Foundation (ASF) under one or more
 * contributor  license agreements.  See  the NOTICE  file distributed
 * with  this  work  for  additional information  regarding  copyright
 * ownership.   The ASF  licenses this  file to  you under  the Apache
 * License, Version  2.0 (the  "License"); you may  not use  this file
 * except in  compliance with the License.   You may obtain  a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the  License is distributed on an  "AS IS" BASIS,
 * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY  KIND, either  express or
 * implied.   See  the License  for  the  specific language  governing
 * permissions and limitations under the License.
 *
 * Copyright 1998-2006 Rogue Wave Software.
 * 
 **************************************************************************/
 
#include <iostream>

#include <codecvte.h>
#include <examples.h>

int main ()
{
    // not used, must be zero-initialized and supplied to facet
    std::mbstate_t state = std::mbstate_t ();

    // three strings to use as buffers
    std::string ins ("\xfc \xcc \xcd \x61 \xe1 \xd9 \xc6 \xe6 \xf5");
    std::string ins2 (ins.size (), '.');
    std::string outs (ins.size () / ex_codecvt ().encoding (), '.');

    // Print initial contents of buffers
    std::cout << "Before:\n"
              << ins << '\n'
              << ins2 << '\n'
              << outs << '\n' << '\n';

    // Create a user defined codecvt fact
    // This facet converts from ISO Latin Alphabet No. 1 (ISO 8859-1)
    // to  U.S. ASCII code page 437.

    // Replace the default codecvt<char, char, mbstate_t>.
    std::locale loc (std::cout.getloc (), new ex_codecvt);

    // Retrieve the facet from the locale.
    typedef std::codecvt<char, char, std::mbstate_t> CodeCvt;
    const CodeCvt& cdcvt = std::use_facet<CodeCvt>(loc);

    // unused, must be provided to codecvt<>::in/out
    const char *const_out_next = 0;
    const char *const_in_next  = 0;
          char *in_next        = 0;
          char *out_next       = 0;

    // convert the buffer
    cdcvt.in (state, ins.c_str (), ins.c_str () + ins.length (), const_in_next,
              &outs [0], &outs [0] + outs.length (), out_next);

    std::cout << "After in:\n"
              << ins << '\n'
              << ins2 << '\n'
              << outs << "\n\n";

    // zero-initialize (unused) state object
    state = std::mbstate_t ();

    // Finally, convert back to the original codeset
    cdcvt.out (state, outs.c_str (), outs.c_str () + outs.length (),
               const_out_next, &ins [0], &ins [0] + ins.length (), in_next);

    std::cout << "After out:\n"
              << ins << '\n'
              << ins2 << '\n'
              << outs << '\n';

    return 0;
}