Range-based loop over an input stream

Question

To iterate over an input stream, we would usually use a std::istream_iterator like so:

typedef std::istream_iterator input_iterato         


        

Answer 1

An obvious approach is to use a simple decorator for your stream providing the type and the necessary interface. Here is how this could look like:

template 
struct irange
{
    irange(std::istream& in): d_in(in) {}
    std::istream& d_in;
};
template 
std::istream_iterator begin(irange r) {
    return std::istream_iterator(r.d_in);
}
template 
std::istream_iterator end(irange) {
    return std::istream_iterator();
}

for (auto const& x: irange(std::ifstream("file") >> std::skipws)) {
    ...
}