C++で引数の数値を進数文字列に変換(C++17必須)

#include <iostream>
#include <iterator>
#include <string>
#include <algorithm>
#include <string_view>
#include <charconv>

std::string to_decimal_string(const int& number, const int& base)
{
    char out[50]{};
    auto begin = std::begin(out);
    auto end = std::end(out);
    std::string res;
    if (auto [ptr, ec] = std::to_chars(begin, end, number, base); ec == std::errc{}) {
        res.assign(begin, ptr - begin);
    }
    return res;
}

int main()
{
    std::cout << to_decimal_string(100, 2) << std::endl;

}