hex encode

hexencode.cpp

#include <string>
#include <vector>
#include <iostream>

using byte = uint8_t;

static std::string hexEncode(const std::vector<uint8_t>& data) {
  std::string result(data.size() * 3, ' ');
  for (size_t i = 0, k = 0; k < result.size(); ++i, k += 3) {
    static const char hex[] = "0123456789abcdef";
    const uint8_t val = data[i];
    result[k + 0] = hex[val >> 4];
    result[k + 1] = hex[val & 15];
  }
  return result;
}

int main() {
  std::string test("CIAO");
  std::vector<uint8_t> vtest(test.begin(), test.end());
  std::cerr << hexEncode(vtest) << "\n";
}