Enum ErasureType 

pub enum ErasureType {
    SelfType,
    SelfRef,
    SelfRefMut,
    SelfAssoc {
        assoc_name: String,
        bound_trait_id: Option<u32>,
    },
    Generic {
        name: String,
        args: Vec<ErasureType>,
    },
    Reference {
        mutable: bool,
        inner: Box<ErasureType>,
    },
    MethodGeneric {
        name: String,
    },
    Concrete {
        type_token: u32,
    },
}

Storage-tier projection of the method-signature types Erase_T operates on. Mirrors the row table in ADR-006 §2.7.24 Q25.C.1:

Input τ	Erase_T(τ)
Self	dyn T
&Self / &mut Self	&dyn T / &mut dyn T
Self::A w/ bound	dyn Bound
Self::A w/o bound	ETO-001 compile error
G<τ₁, ...> w/ erasure-safe G	recurse
method-generic G	KindedSlot + TypeInfo
concrete / builtin	unchanged

Variants

SelfType

Self — boxes into dyn T (the trait being erased).

SelfRef

&Self (immutable) — boxes into &dyn T.

SelfRefMut

&mut Self — boxes into &mut dyn T.

SelfAssoc

Self::A — projection of a Self-associated type. If bound_trait_id is Some, the assoc type’s bound trait id (the type erases to dyn Bound); if None, this is an ETO-001 compile error (associated type without a trait bound cannot be erased).

Fields

assoc_name: String

bound_trait_id: Option<u32>

Generic

An erasure-safe generic constructor (Option/Result/Vec/Box/Arc/ HashMap/HashSet/tuple/user-#[erasure_safe]) with type-argument list to recurse into. name is the constructor’s user-visible name; the emission tier maps this back to its own Type ctor.

Fields

name: String

args: Vec<ErasureType>

Reference

&G<...> / &mut G<...> — reference to a generic. Reference itself is not auto-boxed; recurses into the payload.

Fields

mutable: bool

inner: Box<ErasureType>

MethodGeneric

Method-generic parameter (fn foo<G: Bound>(...)). At dispatch time the call site supplies a KindedSlot payload + a &TypeInfo per generic — see §Q25.C.3.

Fields

name: String

Concrete

A concrete or builtin type (int, string, user-defined struct, closure type, etc.). Carries an opaque token so the emission tier can map back to its richer representation. Erase_T leaves these unchanged.

Fields

type_token: u32

Implementations

impl ErasureType

pub fn rewrite(&self, trait_id: u32) -> Result<RewriteResult, ErasureError>

Apply the Erase_T(τ) substitution per ADR-006 §2.7.24 Q25.C.1. Returns the rewritten type, plus a wrap_targets accumulator describing every Self / Self::A site reached (used by the emission tier to populate VTableEntry::BoxedReturn::wrap_targets).

The trait_id argument is the surrounding trait’s id — used for Self → dyn T (T being the surrounding trait) and as the fallback wrap_as_trait_id for assoc-type erasures.

Returns Err with the ETO error code on unbounded Self::A per §Q25.C.1 row 5.

Trait Implementations

impl Clone for ErasureType

fn clone(&self) -> ErasureType

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ErasureType

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for ErasureType

fn eq(&self, other: &ErasureType) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for ErasureType

impl StructuralPartialEq for ErasureType