is_float_number() throw exception

[ghmchen]

When my yaml file have three level nodes, and the third level node is unfortunately missed in the yaml file. is_float_number() function will throw exception.
Here are my codes:
std::ifstream ifs(YamlPath);
fkyaml::node Root = fkyaml::node::deserialize(ifs);
if (Root["first_level_nodes"]["second_level_nodes"]["third_level_nodes"].is_float_number()) //exception thrown here
m_Threshold = Root["first_level_nodes"]["second_level_nodes"]["third_level_nodes"].get_value_ref<double&>();

here is a good yaml file example:
first_level_nodes:
--second_level_nodes:
----third_level_nodes: 12.3a

here is a yaml file example throwing exception
first_level_nodes:
--second_level_nodes:

Is there any way to avoid throwing an exception here?
Thanks,

[fktn-k]

@ghmchen
I guess the function which throws the exception is not is_float_number() but operator[]() since the mapping value at the second level is parsed as a null scalar, not a mapping, when the third level node is missing. What was the exception message?
Assuming my guess is right, one way to avoid the exception in such a case is to check the type of the mapping value beforehand:

auto& SecondLevelNode = Root["first_level_nodes"]["second_level_nodes"];
if (SecondLevelNode.is_mapping() && SecondLevelNode["third_level_nodes"].is_float_number())
    m_Threshold = SecondLevelNode["third_level_nodes"].get_value_ref<double&>();

[ghmchen]

@fktn-k
You are super! Your solution works like a charm!

[fktn-k]

@ghmchen
My pleasure! Feel free to ask anything you need.