Dumb and slow c++ json pretty printer

json_pretty_printer.hpp

void indent_json(std::string &json)
{
	std::stringstream tmp;
	int indent_level = 0;
	char prev = 0;
	
	for (auto it = json.begin(); it < json.end(); it++) {
		switch (*it) {
		case '{':
		case '[':
			indent_level++;
		case ',':
			tmp << *it << '\n';
			for (int i = 0; i < indent_level; i++)
				tmp << "    ";
			break;
		case '}':
		case ']':
			tmp << '\n';
			indent_level--;
			for (int i = 0; i < indent_level; i++)
				tmp << "    ";
			tmp << *it;
			break;
		case '"':
			prev = 0;
			do {
				tmp << *it;
				prev = *it++;
			} while (*it != '"' || prev == '\\');
			tmp << *it;
			break;
		case ' ':
			break;
		case ':':
			tmp << *it << ' ';
			break;
		default:
			tmp << *it;
		}
	}
	json = tmp.str();
}