Macro tera::try_get_value

macro_rules! try_get_value {
    ($filter_name:expr, $var_name:expr, $ty:ty, $val:expr) => { ... };
}

Helper macro to get real values out of Value while retaining proper errors Takes 4 args: filter name, variable name (use value if it's the value the filter is ran on), the expected type and the actual variable