Method exist

src/custom/impl/param.cpp:134–137

}

bool Param::exist(const std::string& name) const {
    return TypedRef(ParamImpl, m_impl.get()).m_vals.find(name) !=
           TypedRef(ParamImpl, m_impl.get()).m_vals.end();
}

std::string Param::to_bytes(void) const {
    std::string res;