Is it OK to use iostreams with int as character-type?

Question

When trying to come up with an answer to this question, I wrote this little test-program:

#include <iostream>
#include <fstream>
#include <vector>
#include <iterator>
#include <algorithm>

void writeFile() {
    int data[] = {0,1,2,3,4,5,6,7,8,9,1000};

    std::basic_ofstream<int> file("test.data", std::ios::binary);
    std::copy(data, data+11, std::ostreambuf_iterator<int>(file));
}

void readFile() {
    std::basic_ifstream<int> file("test.data", std::ios::binary);
    std::vector<int> data(std::istreambuf_iterator<int>(file),
        (std::istreambuf_iterator<int>()));

    std::copy(data.begin(), data.end(), 
              std::ostream_iterator<int>(std::cout, " "));
    std::cout << std::endl;
}


int main()
{
    writeFile();
    readFile();

    return 0;
}

It works as expected, writing the data to the file, and after reading the file, it correctly prints:

0 1 2 3 4 5 6 7 8 9 1000

However, I am not sure if there are any pitfalls (endianess issues aside, you always have these when dealing with binary data)? Is this allowed?

Answer 1

It works as expected.

I'm not sure what you are expecting...

Is this allowed?

That's probably not portable. Streams relies on char_traits and on facets which are defined in the standard only for char and wchar_t. An implementation can provides more, but my bet would be that you are relying on a minimal default implementation of those templates and not on a conscious implementation for int. I'd not be surprised that a more in depth use would leads to problems.