Figuring out if a string will round-trip

[gyorokpeter]

E.g. if I render a string with the value true or 1.1, when parsed back they become a boolean and a number respectively.
Is there a way to determine if a certain string doesn't round trip and therefore needs quotes added when emitting it?

[SGSSGene]

I am not sure what you are asking for.
If you read them with node.as<std::string>() they will roundtrip just fine.

Maybe you can clarify?

[gyorokpeter]

It has been a while since I raised this, and we made a workaround in the meantime, but the situation was roughly this:

• We have a function that takes some object provided by the user and converts it to YAML
• It uses YAML::Emitter's operator<< to output the object
• Previously, if the user object was a string, it would just call out << str, which blindly outputs the string without consideration of whether it has some special format such that when parsed back it turns into something else such as a number, boolean, null etc.
• This was causing problems when the user object was something like ["my", "true", "love"], where the "true" value would be printed out without the quotes, so when parsed back, it would become the boolean value true instead of the string "true"
• The workaround was to create a dedicated "render string" function that matches the input against a laundry list of regexes, such as those for all the number formats, infinities, true/false etc., and if any of them match, does out << YAML::SingleQuoted first. Since this looks like a common operation for anyone who would like to output YAML from user data, I was wondering if there was some level of support in the library itself, such as an "is special value" function that encapsulates the check for whether the string would round-trip without the quotes.