Overrun of data causes unassigned variable to be provided to functions

Could also be broken with all similar functions but logging what I observed:

struct Option<T> {
    bool is_some;
    T value;
} [[format("format_option")]];

fn format_option(Option<auto> option) {
    std::print("{}", option.is_some);
    if (option.is_some) {
        return std::format("Some({})", option.value);
    } else {
        return "None";
    }
};

I can see in pattern data that is_some is true but inside format_option it is false (in the console). Value is also not populated.

Start by reproducing the provided Option and format_option example in the PatternLanguage implementation, then trace how pattern data is passed into functions. Done means the observed is_some and value fields retain their expected values inside format_option, including for similar functions.