Reading in 4 bytes at a time

Question

I have a big file full of integers that I\'m loading in. I\'ve just started using C++, and I\'m trying out the filestream stuff. From everything I\'ve read, it appears I c

Answer 1

To read by 4 bytes from ifstream you could overload operator>> as follows (it is actually a partial specialization of the basic_istream class template so istream_iterator could use operator>> from it. Class basic_ifstream is used here to inherit all input file stream functionality from it):

#include 

typedef unsigned int uint32_t;    
struct uint32_helper_t {};

namespace std {
template
class basic_istream : public basic_ifstream {
public:
    explicit basic_istream(const char* filename, 
        ios_base::openmode mode ) : basic_ifstream( filename, mode ) {}

    basic_istream& operator>>(uint32_t& data) {
        read(&data, 1);
        return *this;
    }
};
} // namespace std {}

Then you could use it in the following way:

std::basic_istream my_file( FILENAME, std::ios::in|std::ios::binary );
// read one int at a time
uint32_t value;
my_file >> value;

// read all data in file
std::vector data;
data.assign( std::istream_iterator(my_file),
  std::istream_iterator() );