codecvt and stringstream

[FabioAng]

I implemented a codecvt facet (extracted from TCPL) but while it works well
with 'ifstream' it doesn't work at all with 'stringstream'.
Am I missing anything ? I tested it with MSVC 7.1

The code below shows what I'm trying to do:

#include <stdio.h>
#ifdef _WIN32
#include <io.h>
#else
#include <stdlib.h>
#endif

#include <string>
#include <iostream>
#include <sstream>
#include <fstream>

using namespace std;

class Cvt_to_upper : public codecvt<char, char, mbstate_t>
{
typedef codecvt<char, char, mbstate_t> Base;

public:
explicit Cvt_to_upper(size_t refs = 0)
: Base(refs)
{
}

protected:
result do_in(state_type&,
const extern_type* from, const extern_type* from_end,
const extern_type*& from_next,
intern_type* to, intern_type* to_end,
intern_type*& to_next) const
{
while (from < from_end && to < to_end)
*to++ = toupper(*from++);

to_next = to;
from_next = from;
return from == from_end ? ok : partial;
}

bool do_always_noconv() const throw()
{
return false;
}
};

int main(int argc, char* argv[])
{

locale loc1;
locale loc (loc1, new Cvt_to_upper);

stringstream oss;
oss.imbue(loc);

char name[] = "charupperXXXXXX";
mktemp(name);

string lower_str("abcd");
string upper_str;

{
ofstream out(name);

out << lower_str;
oss << lower_str;
}
{
ifstream in;
in.imbue(loc);
in.open(name);

in >> upper_str;
cout << "using ifstream: " << upper_str << std::endl;
oss >> upper_str;
cout << "using stringstream: " << upper_str << std::endl;
}

remove(name);
}

 

[P.J. Plauger]

I implemented a codecvt facet (extracted from TCPL) but while it works well
with 'ifstream' it doesn't work at all with 'stringstream'.
Am I missing anything ? I tested it with MSVC 7.1

Yes. Only basic_filebuf (used by ifstream) uses codecvt.
To use a codecvt facet with stringstream, you need something
like our wbuffer_convert. See:

http://www.dinkumware.com/manuals/?manual=compleat&page=wbuffer.html

P.J. Plauger
Dinkumware, Ltd.
http://www.dinkumware.com