Enum ArrayLenReason 

pub enum ArrayLenReason {
    NotLiteralOrName,
    NotAnIntegerLiteral,
    IntegerOutOfRange,
    NotABareName,
    NotAMarkedConst,
    ConstIsNotALiteral,
    ForeignSourceConst {
        const_crate: String,
        item_crate: String,
    },
}

Why an array length was refused.

Variants

NotLiteralOrName

Not a literal and not a plain name: arithmetic, a cast, a call, a block, a match, a closure — anything with structure the grammar lacks.

NotAnIntegerLiteral

A literal that is not a non-negative integer.

IntegerOutOfRange

An integer literal too large for usize.

NotABareName

A path with more than one segment, a qualified self, or a leading :: — crate::limits::MAX, usize::MAX, <Holder>::N, ::MAX.

A length names a #[prebindgen] const, and those live in one flat, uniquely-named namespace, so the bare name is the complete address. Any longer path either restates that (crate::limits::MAX) or reaches somewhere the frontend cannot follow — a module it does not index, an associated const it never captured, a foreign crate. Neither can be reduced to a number, and guessing between them is how a length silently becomes the wrong one.

NotAMarkedConst

A bare name that is not a #[prebindgen] const.

The generated crate sees only what the macro exposed, so an unmarked const is not merely unqualifiable — it does not exist downstream.

ConstIsNotALiteral

A #[prebindgen] const whose own initializer is not an integer literal.

build.rs cannot evaluate it, and a destination language that needs the count cannot either. Hoist the arithmetic into the value the const is computed FROM, or write the number.

ForeignSourceConst

A #[prebindgen] const from a different source crate than the item using it.

Uniqueness holds across the marked namespace only, so a bare name in one source crate can collide with an unmarked name of its own — the frontend would silently bind to the other crate’s value. Requiring the length’s const to come from the item’s own crate makes that unrepresentable.

Fields

const_crate: String

Crate the const was marked in.

item_crate: String

Crate the item using it came from.

Trait Implementations

impl Clone for ArrayLenReason

fn clone(&self) -> ArrayLenReason

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ArrayLenReason

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

Formats the value using the given formatter.

impl Eq for ArrayLenReason

impl PartialEq for ArrayLenReason

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ArrayLenReason