Base10 => Base2, Base8, Base16

#include <iostream>
#include <string>
using namespace std;
template<typename Type> constexpr bool is_integer =
    is_same<Type, long long>::value || is_same<Type, unsigned long long>::value ||
    is_same<Type, long>::value || is_same<Type, unsigned long>::value ||
    is_same<Type, int>::value || is_same<Type, unsigned>::value ||
    is_same<Type, short>::value || is_same<Type, unsigned short>::value;

template<typename Integer> auto convert_base(Integer number, const int base) {
    static_assert(is_integer<Integer>, "The value must be an integer type!");
    const char digits[] = "0123456789ABCDEF";
    string box;
    auto save = number;
    if (number < 0) {
        auto type = string(typeid(number).name());
        if (type == "short"s) {
            auto n = static_cast<unsigned short>(abs(numeric_limits<Integer>::min() - number)) + numeric_limits<Integer>::max() + 1;
            while (n) {
                box = digits[n % base] + box;
                n /= base;
            }
        }
        if (type == "int"s) {
            auto n = static_cast<unsigned>(abs(numeric_limits<Integer>::min() - number)) + numeric_limits<Integer>::max() + 1;
            while (n) {
                box = digits[n % base] + box;
                n /= base;
            }
        }
        if (type == "long"s) {
            auto n = static_cast<unsigned long>(abs(numeric_limits<Integer>::min() - number)) + numeric_limits<Integer>::max() + 1;
            while (n) {
                box = digits[n % base] + box;
                n /= base;
            }
        }
        if (type == "__int64"s) {
            auto n = static_cast<unsigned __int64>(abs(numeric_limits<Integer>::min() - number)) + numeric_limits<Integer>::max() + 1;
            while (n) {
                box = digits[n % base] + box;
                n /= base;
            }
        }
    } else {
        while (number) {
            box = digits[number % base] + box;
            number /= base;
        }
    }
    if (base == 2) box = "0b" + box;
    else if (base == 8) box = '0' + box;
    else if (base == 16) box = "0x" + box;
    else box = to_string(save);
    return box;
}
int main() {
    long a = 127;
    auto ab = convert_base(a, 2);
    auto ao = convert_base(a, 8);
    auto ah = convert_base(a, 16);
    cout << ab << '\n' << ao << '\n' << ah << '\n';
    long long b = -127;
    auto bb = convert_base(b, 2);
    auto bo = convert_base(b, 8);
    auto bh = convert_base(b, 16);
    cout << bb << '\n' << bo << '\n' << bh << '\n';
    auto x = 555;
    auto xx = convert_base(x, 12);
    cout << xx << '\n';
    cin.get();
}