Enum ExtractionMetadata 

pub enum ExtractionMetadata {
    Target {
        type_id: TypeId,
        offset: usize,
        identifier: &'static str,
    },
    Nested {
        type_id: TypeId,
        offset: usize,
        nested: &'static [ExtractionMetadata],
        identifier: &'static str,
    },
}

Metadata describing how to extract types from an entity structure.

Variants

Target

Direct target at a specific offset.

Fields

type_id: TypeId

offset: usize

identifier: &'static str

Nested

Nested extractable type with its own metadata.

Fields

type_id: TypeId

offset: usize

nested: &'static [ExtractionMetadata]

identifier: &'static str

Implementations

impl ExtractionMetadata

pub const fn new<T: Extractable>(offset: usize) -> Self

Create metadata for a direct target type.

pub const fn new_nested<T: Extractable>( offset: usize, nested: &'static [ExtractionMetadata], ) -> Self

Create metadata for a nested extractable type.

pub const fn is_has<List: Extractable, Target: Extractable>() -> bool

Compile-time check whether List contains Target in its extraction metadata.

This function is designed to be called at the beginning of functions that may panic. Since const panics don’t support #[track_caller], it’s best to place this check at the start of public API functions for better error reporting.

Implementation Note

Uses string-based identifier comparison instead of TypeId::eq() because:

• TypeId::eq() is not yet stable in const context (as of Rust 1.83)
• type_name() is also not const-stable
• String comparison with IDENTIFIER (module_path + struct_name) provides the same uniqueness guarantee while being const-evaluable

pub const fn has_val(&self, identifier: &str) -> bool

pub fn flatten(list: &[ExtractionMetadata]) -> FxHashMap<TypeId, usize>

Flatten nested metadata into a single HashMap of type -> offset mappings.