while(! queue.empty()) {
				std::string op;

				const auto token = queue.front();
				queue.pop_front();
				switch(token.type) {
					case Token::Type::Number:
						stack.push_back(std::stoi(token.str));
						op = "Push " + token.str;
						break;

					case Token::Type::Operator:
					{
						const auto rhs = stack.back();
						stack.pop_back();
						const auto lhs = stack.back();
						stack.pop_back();

						switch(token.str[0]) {
							default:
								printf("Operator error [%s]\n", token.str.c_str());
								exit(0);
								break;
							case '^':
								stack.push_back(static_cast<char>(pow(lhs, rhs)));
								//stack.push_back(static_cast<int>(pow(lhs, rhs)));
								break;
							case 'r':
								//stack.push_back(static_cast<int>(sqrt(rhs))); //square root
								//stack.push_back(static_cast<int>(pow(rhs, 1/lhs))); //nth root
								//stack.push_back(pow(rhs, 1.0 / lhs));
								//stack.push_back(static_cast<signed char>(pow(rhs, 1.0/lhs))); //nth root
								stack.push_back(char(pow(rhs, 1.0/lhs))); //nth root
								break;
							case '*':
								//stack.push_back(lhs * rhs);
								stack.push_back(static_cast<char>(lhs * rhs));
								break;
							case '/':
								//stack.push_back(lhs / rhs);
								//stack.push_back(rational(lhs, rhs)); // TODO - fix rationalizing fractions
								//stack.push_back(divide(lhs, rhs));
								if(lhs%rhs == 0)
									stack.push_back(static_cast<char>(lhs / rhs));
									//stack.push_back(lhs / rhs);
								else
									stack.push_back(static_cast<char>(lhs / rhs));
									//stack.push_back(lhs / rhs);

									//evenly_divisible = false;
									//return lhs, rhs;
								break;
							case '+':
								stack.push_back(static_cast<char>(lhs + rhs));
								//stack.push_back(lhs + rhs);
								break;
							case '-':
								stack.push_back(static_cast<char>(lhs - rhs));
								//stack.push_back(lhs - rhs);
								break;
							case 'u':
								//stack.push_back(static_cast<char>((-1) * rhs));
								stack.push_back(static_cast<char>(-rhs));
								//stack.push_back(static_cast<signed int>((-1) * rhs));
								// TODO add negative values possibility
								break;