Deserializing when iterating over children()

[ftpronk]

I'm trying to extract a number of variables stored in a yaml file. As the number of values/names is unknown beforehand, I'm transversing through the yaml tree. (In this case, it happens to be a flat tree)

Is there a way to deserialize a child node to a c++ type? I've managed with a direct tree['key'] access, but not from ryml::Node type.
This is the best I've come up with, but it's a bit clunky..

string buffer = readFile(argv[1]);
ryml::Tree tree = ryml::parse_in_place(ryml::to_substr(buffer));
auto root_ref = tree.rootref();

unordered_map<string, double> remap;

for (auto child: root_ref.children()) {
  if (child.has_key() && child.has_val()) {
    string key;
    ryml::from_chars(child.key(), &key);
    root_ref[child.key()] >> remap[key];
  }
}

As a bonus, is there a simpler way to convert a csubstr to a std::string?

[biojppm]

Sorry for the late reply, missed this notification.

There are several different ways to do that, and they are documented in the quickstart, so have a look over there. Specifically, in these sample functions:

void sample_user_scalar_types();    ///< serialize/deserialize scalar (leaf/string) types
void sample_user_container_types(); ///< serialize/deserialize container (map or seq) types
void sample_std_types();            ///< serialize/deserialize STL containers

A couple of notes about your code.

    root_ref[child.key()] >> remap[key];
// Don't do this, you are doing a double lookup.
// root_ref[child.key()] resolves to child, so just do the following instead:
    child >> remap[key];

Now to get the key, use the ryml::key() tag type:

child >> ryml::key(key);

And reuse the key string to save you n allocations/deallocations:

std::string key;
for (auto child: root_ref.children()) {
  if (child.has_key() && child.has_val()) {
    child >> ryml::key(key);
    child >> remap[key];
  }
}

As for deserializing into the container, after reading the quickstart, you should look at the c4/yml/std/map.hpp header providing interop with std::map which is similar to the std::unordered_map you are using.

[ftpronk]

Thank you for coming back to me. I'll try that out, and dig through the links you added.