Unexpected results with std::ofstream binary write

std::ios::binary promises to not do any line-end conversions on the stream (and some other small behavioral differences with text streams).

You could look at

• Boost Serialization http://www.boost.org/doc/libs/1_53_0/libs/serialization/doc/index.html
• Boost Spirit binary generators http://www.boost.org/doc/libs/1_53_0/libs/spirit/doc/html/spirit/karma/reference/binary/
• Using ofstream::write(…) to manually write the bytes

Here’s an example using Boost Spirit Karma (assuming Big-Endian byte ordering):

#include <boost/spirit/include/karma.hpp>
namespace karma = boost::spirit::karma;

int main()
{
    int i = 10;
    char c="c";
    float f = 30.40f;

    std::ostringstream oss(std::ios::binary);
    oss << karma::format(
            karma::big_dword << karma::big_word << karma::big_bin_float, 
            i, c, f);

    for (auto ch : oss.str())
        std::cout << std::hex << "0x" << (int) (unsigned char) ch << " ";
    std::cout << "\n";
}

This prints

0x0 0x0 0x0 0xa 0x0 0x63 0x41 0xf3 0x33 0x33