Struct FieldAssignMismatch 

pub struct FieldAssignMismatch {
    pub root: String,
    pub root_ty: Ty,
    pub path: Vec<Name>,
    pub op: AssignOp,
    pub found: Ty,
}

One statically-checkable type mismatch at a dotted struct-field assignment target (issue #1900, split from #1864/#1877 — PR #1899’s own check_declared_assign_target explicitly excludes a multi-segment target, since a dotted target’s declared type is its root’s shape, not the field’s).

Body inference resolves only the ROOT’s declared type here (ctx.globals for a VAR/CONST, or an annotated Param/Temp’s ascription — see body::InferPass::check_declared_field_assign_target’s doc) — it has no struct-shape table of its own (the firewall: a body never reads project-wide STRUCT declarations), so path is recorded unresolved. structs::check_assignments (strict-mode-only) walks path against structs::declared_shapes/ShapeInfo to resolve the specific field’s declared type and reports E063.

Fields

root: String

The root local/global’s bare display name (p in p.x = expr).

root_ty: Ty

The root’s resolved declared type — Ty::Struct(name) in the classifiable case; anything else (Unknown, a scalar/collection) is never recorded as a fact at all (see the recording site’s own “Unknown never disagrees” guard).

path: Vec<Name>

The field-access chain past the root, in source order (p.x → [x], p.inner.x → [inner, x]) — each segment’s own Name carries the range a per-field diagnostic should point at.

op: AssignOp

The assignment’s operator (=, +=, …). Carried alongside found (issue #1900 review finding) so structs::check_field_assign_mismatch — the only place the field’s declared type is ever resolved — can apply the same += string-numeric display-concat carve-out Stmt::Assignment’s own arm applies for a bare target: this body- inference pass only knows the ROOT’s type when the fact is recorded, not the field’s, so the carve-out can’t be decided here.

found: Ty

The RHS’s statically inferred type.

Trait Implementations

impl Clone for FieldAssignMismatch

fn clone(&self) -> FieldAssignMismatch

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FieldAssignMismatch

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

Formats the value using the given formatter.

impl Eq for FieldAssignMismatch

impl PartialEq for FieldAssignMismatch

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for FieldAssignMismatch