Editing Elias omega coding (section)

=== Encoding ===
<syntaxhighlight lang="cpp" line="1">// elias_omega_encode is written as a template function taking in an integer
// type parameter, because Integer can be a big integer class, and Elias omega
// encoding will still encode it extremely efficiently (10^10000 only uses 23
// bits more than the binary representation of 10^10000)

#include <vector>

template <class Integer>
constexpr std::vector<bool> little_endian_binary(Integer num){
    std::vector<bool> bits{};
    while (num != 0){
        bits.push_back(num & 0b1u);
        num >>= 1;
    }
    return bits;
}

constexpr std::vector<bool> concat(std::vector<bool> l, std::vector<bool> r){
    for (bool const i : r){
        l.push_back(i);
    }
    return l;
}

////////////////////////////////////////////////////////////////////////////////
// TEMPLATE PARAMETERS                                                        //
// Integer: Type of num                                                       //
////////////////////////////////////////////////////////////////////////////////
// PARAMETERS                                                                 //
// num: Integer storing a positive integer to convert to Elias omega encoding //
////////////////////////////////////////////////////////////////////////////////
// RETURNS                                                                    //
// std::vector<bool> storing Elias omega encoding of num                      //
////////////////////////////////////////////////////////////////////////////////
// EXCEPTIONS                                                                 //
// std::range_error if num is <= 0, as num must be >= 1                       //
// std::bad_alloc if memory runs out                                          //
// Any exception thrown by Integer bitwise or conversion operators            //
////////////////////////////////////////////////////////////////////////////////
template <class Integer>
constexpr std::vector<bool> elias_omega_encode(Integer num){
    if (num <= 0){
        throw std::range_error("elias_omega_encode expects a value >= 1");
    }
    std::vector<bool> bits = {false};
    while (num != 1){
        std::vector<bool> le_binary = little_endian_binary(std::move(num));
        auto const sizem1 = le_binary.size() - 1;
        bits = concat(std::move(le_binary), std::move(bits));
        num = static_cast<Integer>(sizem1);
    }
    return bits;
}</syntaxhighlight>