For json marshalling, I would defer to the underlying type's marshalling if it's present, and return `null` otherwise.
to use a tired example: when getting a value out of a map via some `myMap.get(key)`, you may want to distinguish "not present" = `None` and "present, with value null" = `Some(null)`
the right solution is to just not have nulls in the first place, then there's no problem ;)
Some(null) is not a valid result.
The whole point of the Option type is to let you know:
a) we got a result: Some(value)
b) there is no result: None
struct Foo;
fn main() {
let option_with_null: Option<*const Foo> = Some(std::ptr::null());
dbg!(option_with_null);
dbg!(option_with_null.is_none());
}
[src/main.rs:6] option_with_null = Some(
0x0000000000000000,
)
[src/main.rs:7] option_with_null.is_none() = false
> Some(null) is not a valid result.
It is a valid result. Null pointer and Option::None are still different things, is all.