Returning references with AsString method

[Pepiloto]

Description

Why returning a copy instead of a reference in the AsString method in struct Node ?
String AsString() const { return std::get<String>(*this); }
It's a good practice to return references instead of copies.

Is your feature request related to a problem? Please describe.

I'm frustrated because I can't return const references with my configuration because it's causing a warning during compilation.

Describe the solution you'd like

Return references or const references.

[rojas-diego]

We'll look into it today! Thanks