dlib C++ Library - unicode.cpp

// Copyright (C) 2008 Keita Mochizuki, Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#ifndef DLIB_UNICODe_CPp_
#define DLIB_UNICODe_CPp_
#include "unicode.h"
#include <cwchar>
#include "../string.h"
#include <vector>
namespace dlib
{
 void unichar_to_surrogate_pair(unichar input, unichar &first, unichar &second)
 {
 using namespace unicode_helpers;
 first = ((input - SMP_TOP) >> VALID_BITS) | SURROGATE_FIRST_TOP;
 second = (input & SURROGATE_CLEARING_MASK) | SURROGATE_SECOND_TOP;
 }
 template <int N> struct ustring2wstr
 {
 };
 // for the environment of sizeof(wchar_t) == 2 (i.e. Win32)
 template <> struct ustring2wstr<2>
 {
 wchar_t *wstr;
 size_t wlen;
 ustring2wstr(const ustring &src){
 wlen = 0;
 for (size_t i = 0; i < src.length(); ++i)
 {
 if (src[i] < unicode_helpers::SMP_TOP) wlen++;
 else wlen += 2;
 }
 wstr = new wchar_t[wlen+1];
 wstr[wlen] = L'0円';
 size_t wi = 0;
 for (size_t i = 0; i < src.length(); ++i)
 {
 if (src[i] < unicode_helpers::SMP_TOP)
 {
 wstr[wi++] = (wchar_t)src[i];
 }
 else
 {
 unichar high, low;
 unichar_to_surrogate_pair(src[i], high, low);
 wstr[wi++] = (wchar_t)high;
 wstr[wi++] = (wchar_t)low;
 }
 }
 }
 ~ustring2wstr()
 {
 delete[] wstr;
 }
 };
 // for the environment of sizeof(wchar_t) == 4 (i.e. Unix gcc)
 template <> struct ustring2wstr<4>
 {
 const wchar_t *wstr;
 size_t wlen;
 ustring2wstr(const ustring &src){
 wstr = (const wchar_t *)(src.c_str());
 wlen = src.size();
 }
 };
// ----------------------------------------------------------------------------------------
 const ustring convert_utf8_to_utf32(const std::string& str)
 {
 return convert_to_utf32<char>(str);
 }
// ----------------------------------------------------------------------------------------
 const ustring convert_wstring_to_utf32(const std::wstring& str)
 {
 return convert_to_utf32<wchar_t>(str);
 }
// ----------------------------------------------------------------------------------------
 const std::wstring convert_utf32_to_wstring(const ustring &src)
 {
 ustring2wstr<sizeof(wchar_t)> conv(src);
 std::wstring dest(conv.wstr);
 return dest;
 }
// ----------------------------------------------------------------------------------------
 const std::wstring convert_mbstring_to_wstring(const std::string &src)
 {
 std::vector<wchar_t> wstr(src.length()+5);
 std::mbstowcs(&wstr[0], src.c_str(), src.length()+1);
 return std::wstring(&wstr[0]);
 }
// ----------------------------------------------------------------------------------------
 const std::string convert_wstring_to_mbstring(const std::wstring &src)
 {
 using namespace std;
 std::string str;
 str.resize((src.length() + 1) * MB_CUR_MAX);
 wcstombs(&str[0], src.c_str(), str.size());
 return std::string(&str[0]);
 }
// ----------------------------------------------------------------------------------------
}
#endif // DLIB_UNICODe_CPp_