std::string moon::wstring_to_string(const std::wstring& ws)
{
std::locale sys_loc("");
const wchar_t* src_wstr = ws.c_str();
const size_t MAX_UNICODE_BYTES = 4;
const size_t BUFFER_SIZE =
ws.size() * MAX_UNICODE_BYTES + 1;
std::string extern_buffer(BUFFER_SIZE,0);
const wchar_t* intern_from = src_wstr;
const wchar_t* intern_from_end = intern_from + ws.size();
const wchar_t* intern_from_next = 0;
char* extern_to = &extern_buffer[0];
char* extern_to_end = extern_to + BUFFER_SIZE;
char* extern_to_next = 0;
typedef std::codecvt<wchar_t, char, mbstate_t> CodecvtFacet;
CodecvtFacet::result cvt_rst =
std::use_facet<CodecvtFacet>(sys_loc).out(
out_cvt_state,
intern_from, intern_from_end, intern_from_next,
extern_to, extern_to_end, extern_to_next);
if (cvt_rst != CodecvtFacet::ok) {
switch(cvt_rst) {
case CodecvtFacet::partial:
std::cerr << "partial";
break;
case CodecvtFacet::error:
std::cerr << "error";
break;
case CodecvtFacet::noconv:
std::cerr << "noconv";
break;
default:
std::cerr << "unknown";
}
std::cerr << ", please check out_cvt_state."
<< std::endl;
}
return std::move(extern_buffer);
}
std::wstring moon::string_to_wstring(const std::string& s)
{
std::locale sys_loc("");
const size_t BUFFER_SIZE = s.size() + 1;
std::wstring intern_buffer(BUFFER_SIZE, 0);
const char* extern_from_next = 0;
wchar_t* intern_to_next = 0;
typedef std::codecvt<wchar_t, char, mbstate_t> CodecvtFacet;
CodecvtFacet::result cvt_rst =
std::use_facet<CodecvtFacet>(sys_loc).in(
in_cvt_state,
s.c_str(),
s.c_str() + s.size(),
extern_from_next,
&intern_buffer[0],
&intern_buffer[0] + intern_buffer.size(),
intern_to_next);
if (cvt_rst != CodecvtFacet::ok) {
switch(cvt_rst) {
case CodecvtFacet::partial:
std::cerr << "partial";
break;
case CodecvtFacet::error:
std::cerr << "error";
break;
case CodecvtFacet::noconv:
std::cerr << "noconv";
break;
default:
std::cerr << "unknown";
}
std::cerr << ", please check in_cvt_state."
<< std::endl;
}
std::wstring result = intern_buffer;
return std::move(intern_buffer);
}
OutS CodeConvert(const InS& ins) {
std::locale sys_loc("");
const In* src_insrc = ins.c_str();
const size_t BUFFER_SIZE = ins.size() * Max_In_Size;
const size_t OUT_SIZE = sizeof(Out);
// TODO:
// reasonable size , it may be too large the allocation to
// on the Out[BUFFER_SIZE]
Out * extern_buffer = new Out[BUFFER_SIZE];
memset(extern_buffer, 0, BUFFER_SIZE * OUT_SIZE);
const In * intern_from = src_insrc;
const In * intern_from_end = intern_from + ins.size();
const In * intern_from_next = 0;
Out * extern_from = extern_buffer;
Out * extern_from_end = extern_from + BUFFER_SIZE;
Out * extern_from_next = 0;
typedef std::codecvt<In, Out, std::mbstate_t> CodeCvtFacet;
// TODO:
// it is required to have the typename in front of the
// CodeCvtFacet
// It is because of the CodeCvtFacet is a dependent scope, which means it required
// to explicitly tell the compiler that the CodeCvtFacet is a type
//
typename CodeCvtFacet::result cvt_rst = std::use_facet<CodeCvtFacet>(sys_loc).out(
out_cvt_state,
intern_from,
intern_from_end,
intern_from_next,
extern_from,
extern_from_end,
extern_from_next
);
if (cvt_rst != CodeCvtFacet::ok) {
switch (cvt_rst) {
case CodeCvtFacet::error:
std::cerr << "partial";
break;
case CodeCvtFacet::partial:
std::cerr << "partial";
break;
case CodeCvtFacet::noconv:
std::cerr << "noconv";
break;
default:
std::cerr << "unknown";
break;
}
std::cerr << ", please check out_cvt_state."
<< std::endl;
}
OutS result = extern_buffer;
delete[] extern_buffer;
return result;
};
