main.cpp

#include <gears/io.hpp>
#include <iostream>

using namespace gears;

int main() {
    int x[] = { 10, 11, 121, -12131, 129128 };
    io::print("{0,10}\t{1,10}\n", "Decimal", "Hexadecimal");
    for(auto&& i : x) {
        io::print("{0,10}\t0x{0,-10:X}\n", i);
    }
}

stdout

   Decimal  Hexadecimal
        10  0xA         
        11  0xB         
       121  0x79        
    -12131  0xFFFFD09D  
    129128  0x1F868