Trait StrictSchema

Source

pub trait StrictSchema {
    // Provided method
    fn strict_top_level_keys() -> Option<&'static [&'static str]> { ... }
}

Expand description

Types parsed at a strict create boundary implement this so the boundary can guard fields that serde_ignored can’t see.

The blanket-ish default returns None (“serde_ignored catches every typo, nothing extra to check”), which is correct for any type WITHOUT a #[serde(flatten)] field. A type that DOES flatten a sub-struct must override it: serde deserialises a flattened parent by buffering all fields into an internal map and handing the leftovers to the flattened field’s deserialiser, and that buffering is opaque to serde_ignored — so an unknown TOP-LEVEL key on a flattening type is silently dropped instead of rejected (#924). Overriding with the complete top-level key set (the type’s own fields AND the flattened struct’s fields) lets the boundary reject those keys explicitly. Nested typos are still caught by serde_ignored as usual.