将typedef short转换为vector（char）

Question

I am new at C++. Does anyone know how to convert typedef short to vector(char) ? Convert decompress to vector (char) .

opusencoder encodedatag;
opus_int16 *decompress = encodedatag.encodedata(...);

Answer 1

I presume you have a short and you want to represent it as a sequence of char s in a vector<char> .

If that's the case, that's my suggestion, with a simple test :)

#include <iostream>
#include <vector>
#include <algorithm>

using opus_int16 = short;

std::vector<char> toVector(opus_int16 arg)
{
    std::vector<char>   converted;
    opus_int16          remainder(0);
    bool                isNegative((arg < 0) ? true : false);

    if (isNegative)
        arg = -arg;

    while (arg != 0)
    {
        remainder = arg % 10;
        arg /= 10;
        converted.push_back(remainder + 48);
    }


    if (isNegative)
        converted.push_back('-');

    std::reverse(converted.begin(), converted.end());

    return converted;
}

int main(int argc, char **argv)
{
    opus_int16 example = -156;

    std::vector<char> test(toVector(example));

    for (auto i : test)
        std::cout << i;

    std::cin.get();

    return 0;
}

Answer 2

Assuming the received shorts are in the endianess of the host and that the short is actually 16 bits (uint16_t would be better) and the chars are expected to be the big endian representation of the shorts, converting shorts to char can be done like this:

std::pair<uint8_t, uint8_t> convert_uint16_to_uint8s(uint16_t in)
{
    std::pair<uint8_t, uint8_t> out;
    out.first = in >> 8;
    out.second = in & 0xff;
    return out;
}

If you know the length of the array, pointed to by decompress, you can iterate over the array and convert each short and push_back each char.

std::vector<uint8_t> output;
for (int i = 0; i < decompress_length; ++i)
{
    std::pair<uint8_t, uint8_t> chars = convert_uint16_to_uint8s(decompress[i];
    output.push_back(chars.first);
    output.push_back(chars.second);
}

(code as example, not compiled or tested)