22inline namespace util {
 
   38    auto it = get_last_value(
key);
 
   39    if (
it != map_.end()) {
 
   43        throw runtime_error{
"missing config key: "s + 
key};
 
   45    return parent_->get(
key);
 
 
   50    auto it = get_last_value(
key);
 
   51    if (
it != map_.end()) {
 
   52        return it->second.c_str();
 
 
   64            map_.emplace(
key, std::move(
val));
 
   88        const string name{next};
 
   92        map_.emplace(name, std::move(
config));