Method to_string

imperative/src/impl/op_def.cpp:97–107

}

std::string OpDef::to_string() const {
    std::string builder = trait()->name;
    builder += "{";
    for (auto&& [name, value] : props(*this)) {
        builder += name;
        builder += ": ";
        builder += value;
        builder += ",";
    }
    return builder + "}";
}

std::string OpDef::name() const {
    return trait()->name;