detail/windows/locale.hpp

0001 // Copyright (c) 2016 Klemens D. Morgenstern
0002 // Copyright (c) 2008 Beman Dawes
0003 //
0004 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0005 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006
0007 #ifndef BOOST_PROCESS_DETAIL_WINDOWS_LOCALE_HPP_
0008 #define BOOST_PROCESS_DETAIL_WINDOWS_LOCALE_HPP_
0009
0010 #include <locale>
0011 #include <boost/core/ignore_unused.hpp>
0012 #include <boost/winapi/file_management.hpp>
0013 #include <boost/winapi/character_code_conversion.hpp>
0014
0015 namespace boost
0016 {
0017 namespace process
0018 {
0019 namespace detail
0020 {
0021 namespace windows
0022 {
0023
0024 //copied from boost.filesystem
0025 class windows_file_codecvt
0026    : public std::codecvt< wchar_t, char, std::mbstate_t >
0027  {
0028  public:
0029    explicit windows_file_codecvt(std::size_t refs = 0)
0030        : std::codecvt<wchar_t, char, std::mbstate_t>(refs) {}
0031  protected:
0032
0033    bool do_always_noconv() const noexcept override { return false; }
0034
0035    //  seems safest to assume variable number of characters since we don't
0036    //  actually know what codepage is active
0037    int do_encoding() const noexcept override { return 0; }
0038
0039    std::codecvt_base::result do_in(std::mbstate_t& state,
0040      const char* from, const char* from_end, const char*& from_next,
0041      wchar_t* to, wchar_t* to_end, wchar_t*& to_next) const override
0042    {
0043      boost::ignore_unused(state);
0044
0045        auto codepage =
0046 #if !defined(BOOST_NO_ANSI_APIS)
0047                ::boost::winapi::AreFileApisANSI() ?
0048                ::boost::winapi::CP_ACP_ :
0049 #endif
0050                ::boost::winapi::CP_OEMCP_;
0051
0052      int count = 0;
0053      if ((count = ::boost::winapi::MultiByteToWideChar(codepage,
0054              ::boost::winapi::MB_PRECOMPOSED_, from,
0055        static_cast<int>(from_end - from), to, static_cast<int>(to_end - to))) == 0)
0056      {
0057        return error;  // conversion failed
0058      }
0059
0060      from_next = from_end;
0061      to_next = to + count;
0062      *to_next = L'\0';
0063      return ok;
0064   }
0065
0066    std::codecvt_base::result do_out(std::mbstate_t & state,
0067      const wchar_t* from, const wchar_t* from_end, const wchar_t*& from_next,
0068      char* to, char* to_end, char*& to_next) const override
0069    {
0070      boost::ignore_unused(state);
0071      auto codepage =
0072 #if !defined(BOOST_NO_ANSI_APIS)
0073                    ::boost::winapi::AreFileApisANSI() ?
0074                        ::boost::winapi::CP_ACP_ :
0075 #endif
0076                      ::boost::winapi::CP_OEMCP_;
0077      int count = 0;
0078
0079
0080      if ((count = ::boost::winapi::WideCharToMultiByte(codepage,
0081                    ::boost::winapi::WC_NO_BEST_FIT_CHARS_, from,
0082                   static_cast<int>(from_end - from), to, static_cast<int>(to_end - to), 0, 0)) == 0)
0083      {
0084        return error;  // conversion failed
0085      }
0086
0087      from_next = from_end;
0088      to_next = to + count;
0089      *to_next = '\0';
0090      return ok;
0091    }
0092
0093    std::codecvt_base::result do_unshift(std::mbstate_t&,
0094        char* /*from*/, char* /*to*/, char* & /*next*/) const override { return ok; }
0095
0096    int do_length(std::mbstate_t&,
0097      const char* /*from*/, const char* /*from_end*/, std::size_t /*max*/) const override { return 0; }
0098
0099    int do_max_length() const noexcept override { return 0; }
0100  };
0101
0102
0103
0104 }
0105 }
0106 }
0107 }
0108
0109
0110
0111 #endif /* BOOST_PROCESS_LOCALE_HPP_ */