C++ (Cpp) codecvt::max_length示例

示例#1

文件： base.hpp 项目： dmlys/extlib

			void to_bytes_step(const std::codecvt<CvtTypes...> & cvt, typename make_to_bytes_context<std::codecvt<CvtTypes...>>::type & ctx)
			{
				ctx.res = cvt.out(ctx.state,
				                  ctx.from_beg, ctx.from_end, ctx.from_stopped,
				                  ctx.to_beg, ctx.to_end, ctx.to_stopped);

				if (ctx.res == std::codecvt_base::partial) {
					//output extern_char buffer contains cvt.max_length or more - input is partial
					ctx.is_partial_input = (ctx.to_stopped - ctx.to_end >= cvt.max_length());
				}
			}

示例#2

文件： codecvt_cast.hpp 项目： jeromewang-github/asio_samples

const std::basic_string<Byte> out(
    const std::basic_string<CharType>& internal_str,
    const std::codecvt<CharType, Byte, mbstate_t>& codecvt)
{
  typedef std::basic_string<CharType> wstring;
  typedef std::basic_string<Byte>     string;
  typedef std::codecvt<CharType, Byte, mbstate_t> codecvt_type;

  string external_str;

  typename wstring::size_type internal_str_size = internal_str.length();
  typename wstring::size_type out_buf_size =
      static_cast<typename wstring::size_type>(codecvt.max_length()) *
          internal_str_size;

#if defined(MA_USE_CXX11_STDLIB_MEMORY)
  detail::unique_ptr<Byte[]> out_buf(new Byte[out_buf_size]);
#else
  detail::scoped_array<Byte> out_buf(new Byte[out_buf_size]);
#endif

  const CharType* first_internal = internal_str.data();
  const CharType* last_internal  = first_internal + internal_str_size;
  const CharType* next_internal  = first_internal;

  Byte* first_external = out_buf.get();
  Byte* last_external  = first_external + out_buf_size;
  Byte* next_external  = first_external;

  // Zero initialized
  typename codecvt_type::state_type state;
  std::memset(&state, 0, sizeof(state));

  typename codecvt_type::result r = codecvt.out(state,
      first_internal, last_internal, next_internal,
      first_external, last_external, next_external);

  if (codecvt_type::ok == r)
  {
    external_str.assign(first_external, next_external);
  }
  else if (codecvt_type::noconv == r)
  {
    external_str.assign(reinterpret_cast<const Byte*>(first_internal),
        reinterpret_cast<const Byte*>(last_internal));
  }
  else
  {
    boost::throw_exception(bad_conversion());
  }

  return external_str;
}

示例#3

文件： codecvt_cast.hpp 项目： 0aps/Legacy-Code

const std::basic_string<Byte> out(
    const std::basic_string<CharType>& internal_str, 
    const std::codecvt<CharType, Byte, mbstate_t>& codecvt)
{
  typedef std::basic_string<CharType> wstring;
  typedef std::basic_string<Byte> string;
  typedef std::codecvt<CharType, Byte, mbstate_t> codecvt_type;

  string external_str;

  typename wstring::size_type internal_str_size = internal_str.length();
  typename wstring::size_type out_buf_size = 
      codecvt.max_length() * internal_str_size;
  boost::scoped_array<Byte> out_buf(new Byte[out_buf_size]);

  const CharType* first_internal = internal_str.data();
  const CharType* last_internal  = first_internal + internal_str_size;
  const CharType* next_internal  = first_internal;

  Byte* first_external = out_buf.get();
  Byte* last_external  = first_external + out_buf_size;
  Byte* next_external  = first_external;

  typename codecvt_type::state_type state(0);

  typename codecvt_type::result r = codecvt.out(state,
      first_internal, last_internal, next_internal,
      first_external, last_external, next_external);

  if (codecvt_type::ok == r)
  {    
    external_str.assign(first_external, next_external);
  }
  else if (codecvt_type::noconv == r)
  {
    external_str.assign(reinterpret_cast<const Byte*>(first_internal), 
        reinterpret_cast<const Byte*>(last_internal));
  }
  else
  {
    boost::throw_exception(bad_conversion());
  }

  return external_str;  
}