How to read file which contains \uxxxx in vc++

Question

I have txt file whose contents are:

\\u041f\\u0435\\u0440\\u0432\\u044b\\u0439_\\u0438\\u043d\\u0442\\u0435\\u0440\\u0430\\u043a\\u0442\\u0438\\u0432\

Answer 1

Here is an example for MSalters's suggestion:

#include 
#include 
#include 
#include 
#include 
#include 
#include 

#include 
#include 
#include 

std::wstring convert_unicode_escape_sequences(const std::string& source) {
  const boost::regex regex("\\\\u([0-9A-Fa-f]{4})");  // NB: no support for non-BMP characters
  boost::scoped_array buffer(new wchar_t[source.size()]);
  wchar_t* const output_begin = buffer.get();
  wchar_t* output_iter = output_begin;
  std::string::const_iterator last_match = source.begin();
  for (boost::sregex_iterator input_iter(source.begin(), source.end(), regex), input_end; input_iter != input_end; ++input_iter) {
    const boost::smatch& match = *input_iter;
    output_iter = std::copy(match.prefix().first, match.prefix().second, output_iter);
    std::stringstream stream;
    stream << std::hex << match[1].str() << std::ends;
    unsigned int value;
    stream >> value;
    *output_iter++ = boost::numeric_cast(value);
    last_match = match[0].second;
  }
  output_iter = std::copy(last_match, source.end(), output_iter);
  return std::wstring(output_begin, output_iter);
}

int wmain() {
  std::locale::global(std::locale(""));
  const std::wstring filename = L"test.txt";
  std::ifstream stream(filename.c_str(), std::ios::in | std::ios::binary);
  stream.seekg(0, std::ios::end);
  const std::ifstream::streampos size = stream.tellg();
  stream.seekg(0);
  boost::scoped_array buffer(new char[size]);
  stream.read(buffer.get(), size);
  const std::string source(buffer.get(), size);
  const std::wstring result = convert_unicode_escape_sequences(source);
  std::wcout << result << std::endl;
}

I'm always surprised how complicated seemingly simple things like this are in C++.