Can a stringstream throw an exception when reading a primitive?

Looking at some old code we have lots of things like the following:

// This is dumb
string do_something(int in)
{
    stringstream out;
    try
    {
        out << std::fixed << in;
    }
    catch(std::exception &e)
    {
        out << e.what();
    }

    return out.str();
}

// Can't we just do this? Can this ever fail?
string do_something_better(int in)
{
    stringstream out;
    out << std::fixed << in;
    return out.str();
}

When a stringstream reads a primitive can it ever throw an exception? What about when reading a string?