Checking if a path exists in a boost property tree

Question

How do I check if a path exists in a property tree?

Example:

boost::property_tree::ptree tree;

// if path doesn't exist, put value
if (/*...*/)
{
    tree.put("my.path.to.thing", true);
}

Answer 1

For a simple solution, you can use get_optional()

According to the documentation, if it exists, it returns the value otherwise it returns an uninitialized optional

Example

boost::property_tree::ptree tree;

// if path doesn't exist, put value
if (!tree.get_optional<bool>("my.path.to.thing").is_initialized())
{
    tree.put("my.path.to.thing", true);
}