How to create a node where key is a dynamic string?

[zexee]

I want to generate node with dynamic string as key, such as:

std::string key = "my_key";
node[ryml::to_csubstr(key)] << 1;

It is compilable but the key is assumed as a static string anyway and the variable key must be kept all the time.
The only solution I can think of is to new std::string to heap and leave it there, but that will cause obvious memory leak.
Is there proper way in the library design?

[biojppm]

You either keep the string around or serialize to the tree's arena. To achieve the latter using the node API, use a combination of operator<< and the disambiguation function ryml::key() (otherwise, it would serialize the string as a val). See the relevant example in the quickstart.

In your case:

std::string k = "mykey";
node << ryml::key(k); // serialize the key to the arena
node << 1; // serialize the value to the arena

or quite simply:

node << ryml::key(key) << 1;

Internally, operator<<(ryml::key(k)) will call tree.copy_to_arena().
You can also do it directly yourself. This sample has the same effect as above:

ryml::csubstr key_copy = node.tree()->copy_to_arena(key);
node[key_copy] << 1;

[zexee]

perfect! thank you!